CHAPTER 17

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FARM LIGHTING BATTERIES SPECIAL INSTRUCTIONS. --------------------------------------------

Although the large Central Station Companies are continually extending their power lines, and are enlarging the territory served by them, yet there are many places where such service is not available. To meet the demand for electrical power in these places, small but complete generating plants have been produced by a number of manufacturers. These plants consist of an electrical generator, an engine, to drive the generator, and a storage battery to supply power when the generator is not running. The complete plants are called "House Lighting," "Farm Lighting," or "Isolated" plants.

The batteries used in these plants differ considerably from the starting batteries used on automobiles. The starting battery is called upon to deliver very heavy currents for short intervals. On the car the battery is always being charged when the car is running at a moderate speed or over. The battery must fit in the limited space provided for it on the car, and must not lose any electrolyte as the car jolts along over the road. It is subjected to both high and low temperatures; and is generally on a car whose owner often does not know that his car has such a thing as a battery until his starting motor some day fails to turn over the engine. All starting batteries have wooden cases (some now use rubber cases), hard rubber jars, and sealed on covers. The case contains all the cells of the battery. Automobile batteries have, therefore, become highly standardized, and to the uninformed, one make looks just like any other.

Farm lighting batteries, on the other hand, are not limited as to space they occupy, are not subjected to irregular charging and discharging, do not need leak proof covers, and are not called upon to delivery very heavy currents for short periods. These facts are taken advantage of by the manufacturers, who have designed their farm lighting batteries to give a much longer life than is possible in the automobile battery. As a result the farm lighting battery differs from the automobile battery in a number of respects.

Jars. Both glass and rubber are used for farm lighting battery jars, and they may or may not have sealed-in covers. Fig. 294 shows a glass jar of an Exide battery having a hard rubber cover, and Fig. 295 shows a Prest-O-Lite glass jar cell having a cover made of lead and antimony. Unsealed glass jars, such as the Exide type shown in Fig. 324, generally have a plate of glass placed across the top to catch acid spray when the cell is gassing. Each jar with its plates and electrolyte forms a complete and separate unit which may easily be disconnected from the other cells of the battery by removing the bolts which join them. In working on a farm lighting battery, the repairman, therefore, works with individual cells instead of the battery as a whole, as is done with automobile batteries.

[Fig. 294 Exide "Delco Light" farming lighting cell with hard rubber cover]

Batteries with sealed jars are generally shipped completely assembled and filled with electrolyte, and need only a freshening charge before being put into service, just as automobile batteries which are shipped "wet" are in a fully charged condition when they leave the factory and need only a charge before being installed on the car.

[Fig. 295 Prest-O-Lite farm lighting cell with lead-antimony cover]

Jars that are not sealed are set in separate glass trays filled with sand, or sometimes the entire battery is set in a shallow wooden box or tray filled with sand. This is necessary because the absence of a sealed cover allows acid spray to run down the outside of the jar and this acid would, of course, attack the wooden shelf and make a dirty, sloppy battery. Batteries using jars without sealed covers cannot be shipped assembled and charged, and hence they require a considerable amount of work and along initial charge to put them in a serviceable condition.

[Fig. 296 Exide farm lighting cell with sealed glass jar]

Farm lighting battery jars are less liable to become cracked than those of automobile batteries because they are set in one place and remain there, and are not jolted about as automobile batteries are. Cracked jars in farm lighting batteries are more easily detected as the jar will be wet on the outside and the acid will wet the shelf or sand tray on which the jar rests.

Batteries with sealed rubber jars are normally assembled four cells in a case or tray, with a nameplate on each tray which gives the type and size of cell. The cells are connected together with lead links which are bolted to the cell posts by means of lead covered bolt connectors.

[Fig. 297 Combination wood and rubber separator used in Delco-Light and Exide Farm light cell]

Plates. Since farm lighting batteries are not required to deliver very heavy currents at any time, the plates are made thicker than in starting batteries, this giving a stronger plate which has a longer life than the starting battery plate.

All makes of starting batteries use the Faure, or pasted plate. This type of plate is also used in many farm lighting batteries, but the Plante plate (see page 27) may also be used. The Exide "Chloride Accumulator" cell, Fig. 323 uses a type of positive plate called the "Manchester" positive as described on page 497.

Separators. Grooved wooden separators are used in some farm lighting batteries, while others use rubber separators, or both rubber and wooden separators. Some use wooden separators which are smooth on both sides, but have dowels pinned to them.

Electrolyte. In a starting battery the specific gravity of the electrolyte of a fully charged cell is 1.280-1.300, no matter what the make of the battery may be. In farm lighting batteries, the different types have different values of specific gravity when fully charged. The usual values are as follows:

(a) Batteries with sealed glass jars 1.210 to 1.250

(b) Batteries with open glass jars 1.200 to 1.250

(c) Batteries with sealed rubber jars 1.260 to 1.280

A brief discussion of specific gravity might be helpful at this point. In any lead acid battery current is produced by a chemical action between the active material in the plates and the water and sulphuric acid in the electrolyte. The amount of energy which can be delivered by the battery depends on the amount of active material, sulphuric acid, and water which enter into the chemical actions of the cell. As these chemical actions take place, sulphuric acid is used up, and hence there must be enough acid contained in the electrolyte to enter into the chemical actions. The amount of water and acid in the electrolyte may be varied, as long as there is enough of each present to combine with the active material of the plates so as to enable the cell to deliver its full capacity. Increasing the amount of acid will result in the plates and separators being attacked and injured by the acid. Increasing the amount of water dilutes the acid, giving a lower gravity, and preventing the Acid from injuring plates and separators. This results in a longer life for the battery, and is a desirable condition. In starter batteries, there is not enough space in the jars for the increased amount of water. In farm lighting batteries, where the space occupied by the battery is not so important, the jars are made large enough to hold a greater amount of water, thus giving an electrolyte which has a lower specific gravity than in starting batteries.

Take a fully charged cell of any starting battery. It contains a set of plates and the electrolyte which is composed of a certain necessary amount of acid and a certain amount of water. If we put the plates of this cell in a larger jar, add the same amount of acid as before, but add a greater amount of water than was contained in the smaller jar, we will still have a fully charged cell of the same capacity as before, but the specific gravity of the electrolyte will be lower.

Charging Equipment. Automobile batteries are being charged whenever the car is running at more than about 10 miles per hour, regardless of what their condition may be.

In farm lighting outfits, the charging is under the control of the operator, and the battery is charged when a charge is necessary. There is, therefore, very much less danger of starving or overcharging the battery. The operator must, however, watch his battery carefully, and charge it as often as may be necessary, and not allow it to go without its regular charge.

The generator of a farm lighting outfit is usually driven by an internal combustion engine furnished with the outfit. The engine may be connected to the generator by a belt, or its shaft may be connected directly to the generator shaft. A switchboard carrying the necessary instruments and switches also goes with the outfit. The charging of farm lighting batteries is very much like the charging of automobile batteries on the charging bench, except that the batteries are at all times connected to switches, by means of which they may be put on the charging line.

Some plants are so arranged that the battery and generator do not provide current for the lights at the same time, lights being out while the battery is charging. In others the generator and battery, in emergency, may both provide current. In others the lights may burn while the battery is being charged; in this case the battery is sometimes provided with counter-electromotive force cells which permit high enough voltage across the battery to charge it and yet limit the voltage across the lamps to prevent burning them out or shortening their life. In some cases the battery is divided into two sets which are charged in parallel and discharged in series.

Relation of the Automobile Storage Battery Man to the Farm Lighting Plant. Owners and prospective owners of farm lighting plants generally know but little about the care or repair of electrical apparatus, especially batteries, which are not as easily understood as lamps, motors or generators. Prospective owners may quite likely call upon the automobile battery repair man for advice as to the installation, operation, maintenance, and repair of his battery and the automobile battery repairman should have little trouble in learning how to take care of farm lighting batteries. The details in which these batteries differ from starting batteries should be studied and mastered, and a new source of business will be opened.

Farm lighting plants in the vicinity should be studied and observed while they are in good working order, the details of construction and operation studied, the layout of the various circuits to lamps, motors, heaters, etc., examined so as to become familiar with the plants. Then When anything goes wrong with the battery, or even the other parts of the plant, there will be no difficulty in putting things back in running order.

Selection of Plant

"Farm Lighting Plant" is the name applied to the small electric plant to be used where a central station supply is not available. Such a plant, of course, may be used for driving motors and heating devices, as well as operating electric lights, and the plant is really a "Farm Lighting and Power Plant."

Make. There are several very good lighting plants on the market and the selection of the make of the plant must be left to the discretion of the owner, or whomever the owner may ask for advice. The selection will depend on cost, whether the plant will fill the particular requirements, what makes can be obtained nearby, on the delivery that can be made, and the service policy of the manufacturer.

Type. Plants are made which come complete with battery, generator, engine, and switchboard mounted on one base. All such a plant requires is a suitable floor space for its installation. Other plants have all parts separate, and require more work to install. With some plants, the generator and engine may be mounted as a unit on one base, with battery and switchboard separate.

The type of jar used in the battery may influence the choice. Jars are made of glass or rubber. The glass jars have sealed covers, or have no covers. The rubber jars generally have a sealed cover. The glass jar has the advantage that the interior may be seen at all times, and the height of the electrolyte and sediment may be seen and the condition of the plates, etc., determined by a simple inspection. This is an important feature and one that will be appreciated by the one who takes care of the battery. Jars with sealed covers, or covers which although not sealed, close up the top of the jar completely have the advantage of keeping in acid spray, and keeping out dirt and impurities. Open jars are generally set in trays of sand to catch electrolyte which runs down the outside walls of the jars. The open jars have the advantage that the plates are very easily removed, but have the disadvantage that acid spray is not kept in effectually, although a plate of glass is generally laid over part of the top of the jar, and that dirt and dust may fall into the jar.

Size. The capacity of storage battery cells is rated in ampere hours, while power consumed by lights, motors, etc., is measured in watt hours, or kilowatt hours. However, the ampere hour capacity of a battery can be changed to watt hours since watt hours is equal to

Watt hours = ampere hours multiplied by the volts

If we have a 16 cell battery, each cell of which is an 80 ampere hour cell, the ampere hour capacity of the entire battery will be 80, the same as that of one of its cells, since the cells are all in series and the same current passes through all cells. The watt hour capacity of the battery will be 32 times 80, or 2560. The ampere hour capacity is computed for the 8 hour rate, that is, the current is drawn from the battery continuously for 8 hours, and at the end of that time the battery is discharged. If the current is not drawn from the battery continuously for 8 hours, but is used for shorter intervals intermittently, the ampere hour capacity of the battery will be somewhat greater. It seldom occurs that in any installation the battery is used continuously for eight hours at a rate which will discharge it in that time, and hence a greater capacity is obtained from the battery. Some manufacturers do not rate their batteries at the 8 hour continuous discharge rate but use the intermittent rate, thus rating a battery 30 to 40 percent higher. Rated in this way, a battery of 16 cells rated at 80 ampere hours at the 8 hour rate would be rated at 112 ampere hours, or 3584 watt hours.

In determining the size of the battery required, estimate as nearly as possible how many lamps, motors, and heaters, etc., will be used. Compute the watts (volts X amperes), required by each. Estimate how long each appliance will be used each day, and thus obtain the total watt hours used per day. Multiply this by 7 to get the watt hours per week. The total watt hours required in one week should not be equal to more than twice the watt hour capacity of the battery (ampere hours multiplied by the total battery voltage) at the eight hour rate. This means that the battery should not require a charge oftener than two times a week.

The capacity of a battery is often measured in the number of lamps it will burn brightly for eight hours. The watts consumed by motors, heaters, etc., may be expressed in a certain number of lamps. The following table will be of assistance in determining the size of the battery required:

Watts Equivalent Number No. Type of Appliance Consumed of 20 Watt Lamps --- ----------------- -------- -----------------

1 16 candle power, Mazda lamp 20 1 2 12 candle power, Mazda lamp 115 3/4 3 Electric Fan, small size 75 4 4 Small Sewing machine motor 100 5 5 Vacuum cleaner 160 8 6 Washing machine 200 10 7 Churn, 1/6 h.p. 200 10 8 Cream Separator, 1/6 h.p. 200 10 9 Water pump 1/6 h.p. 200 10 10 Electric water heater, small 350 18 11 Electric toaster 525 26 12 Electric stove, small 600 30 13 Electric iron 600 30 14 Pump, 1/2 h.p. 600 30

From the foregoing table we can determine the current consumption of the various appliances:

Amps at 32 Amps at 110 No. Watts Volts Volts --- ----- ---------- ------------ 1 20 0.625 0.18 2 15 0.47 0.14 3 75 2.34 6.80 4 100 3.125 0.90 5 160 5.00 1.44 6 200 6.25 1.80 7 200 6.25 1.80 8 200 6.25 1.80 9 200 6.25 1.80 10 350 11.00 3.20 11 525 16.4 4.77 12 600 18.75 5.40 13 600 18.75 5.40 14 600 18.75 5.40

The following tables show how long the battery will carry various currents continuously:

[Images: various charts/tables]

Location of Plant

The various appliances should be placed as near to each other as possible. The lights, of course, must be placed so as to illuminate the different rooms, barns, etc., but the power devices should be placed as close as possible to each other and to the plant. The purpose of this is to use as little wire as possible between the plant and the various appliances so as to prevent excessive voltage drop in the lines.

Wiring

The wires leading to the various appliances should be large enough so that not more than one or two volts are lost in the wires. To obtain the resistance of the wire leading to any appliance, use the following equation:

Knowing the resistance of the wire, and the total length of the two wires leading from the plant to the appliance, the size of the wire may be obtained from a wiring table.

Rubber insulated copper wire covered with a double braid should preferably be used, and the duplex wire is often more convenient than the single wire, especially in running from one building to another. Wiring on the inside of buildings should be done neatly, running the wires on porcelain insulators, and as directly to the appliance as possible. The standard rules for interior wiring as to fuses, soldering joints, etc., should be followed.

Installation

(See also special instructions for the different makes, beginning page 460.)

The room in which the plant is installed should be clean, dry, and well ventilated. It should be one which is not very cold in winter, as a cold battery is very sluggish and seems to lack capacity. If possible, have the plant in a separate room in order to keep out dirt and dust. If no separate room is available, it is a good plan to build a small room in a corner of a large room. Keep the room clean and free of miscellaneous tools and rubbish.

If the entire plant comes complete on one base, all that is necessary is to bolt the base securely to the floor, which should be as nearly level as possible. If the battery is to be installed separately, build a rack. Give the rack several coats of asphaltum paint to make it acid proof. The location of the battery rack should be such that the rack will be:

(a) Free from vibration.

(b) At least 3 feet from the exhaust pipe of engine.

(c) Far enough away from the wall to prevent dirt or loose mortar from dropping on the cells.

Figs. 298 and 299 illustrate two types of battery racks recommended for use with farm light batteries. The stair-step rack is most desirable where there is sufficient room for its installation. Where the space is insufficient to make this installation, use the two-tier shelf rack. The racks should be made from 1-1/2 or 2 inch boards.

[Fig. 298 "Stair-Step" rack for farm lighting battery]

The cells may be placed on the battery rack with either the face or the edges of the plates facing out. The latter method requires a shorter battery rack and is very desirable from the standpoint of future inspections. In very dark places, it is more desirable to have the surface of the plates turned out to enable the user to see when the cells are bubbling during the monthly equalizing charge. Either method is satisfactory.

All metal parts such as pipes, bolt heads, etc., which are near the battery should be given at least three coats of asphaltum paint. Care must be taken not to have an open flame of any kind in the battery room, as the hydrogen and oxygen gases, given off as a battery charges may explode and cause injury to the person and possible severe damage to the battery. When making an installation, it is always a good plan to carry the following material for taking care of spillage and broken jars:

1. 1 Thermometer 2. 2 Series Cells 3. 6 Battery Bolts and Nuts 4. 1 Hydrometer Syringe 5. 2 Gallons distilled water 6. 1 Jar Vaseline 7. 1 Gallon 1.220 specific gravity electrolyte

[Fig. 299 Installation of a Delco-Light plant, showing two-tier shelf rack for battery]

When a battery arrives at the shipping destination, the person lifting this shipment should remove the slats from the top of each crate and inspect each cell for concealed damage, such as breakage: Should any damage be discovered, it is important that a notation covering this damage be made and signed by the freight agent on the freight bill. This will enable the customer or dealer to make a claim against the railroad for the amount of damage. If a notation of this kind is not made before the battery is lifted, the dealer will be forced to stand the expense of repairing or replacing the damaged cells.

When removing cells from a crate, avoid lifting them by the terminal posts as much as possible. This causes the weight of the electrolyte and jar to pull on the sealing compound between the jar and cover, and if the sealing is not absolutely tight, the jar and electrolyte may fall from the cover. A cell should never be carried using the terminal posts as handles. The hand should be put underneath the jar.

Sometimes a battery will arrive with electrolyte spilled from some of the cells. If spillage is only about one-half to one inch down on the plates of three or four cells, this spillage may be replaced by drawing a little electrolyte out of each cell of the other full cells in the set. Oftentimes several cells will have electrolyte extending above the water line, which will aid greatly in making up any loss in other cells. After all cells have been drawn on to fill up the ones that are spilled, the entire set may then have its electrolyte brought up to the water line by adding distilled water.

Very carefully adjust spillage of pilot cells (Delco), as it is very important that the specific gravity of the pilot cells be left as near 1.220 as possible.

In case the spillage is more than one inch below the top of plates or glass broken, remove cell and install a new cell in its place. The spilled or broken cell must not be used until given special treatment.

Connecting Cells

Before connecting up the cells the terminals should be scraped clean for about 11/2 inches on both sides. An old knife or rough file is suitable for doing this work. After the terminals are thoroughly brightened, they should be covered with vaseline. The bolts and nuts used in making the connections on the battery should also be coated with vaseline. The vaseline prevents and retards corrosion, which is harmful to efficient operation.

If a new battery is to be installed in parallel with one already in service, connections should be made so that each series will consist of half new and half old cells. The pilot cells for the new battery should be placed in one series and that for the old battery in the other, unless local conditions may make some other arrangement desirable.

A drop light must always be provided to enable the user to inspect his battery, particularly when giving the monthly equalizing charge.

Initial Charge

When a battery is connected to the plant, it should be given a proper INITIAL CHARGE before any power or lights are used.

Batteries shipped filled with electrolyte are fully charged before leaving the factory. As soon as a storage battery cell of any type or make is taken off charge and stands idle for a considerable length of time, some of the acid in the electrolyte is absorbed by the plates, thereby lowering the gravity and forming sulphate on the plates. This process is very gradual, but it is continuous, and unless the acid is completely driven out of the plates by charging before the battery is used, the battery will not give as good service as the user has a right to expect. Due to the time required in shipment, the above

## action has a chance to take place, which makes it necessary to give

the initial charge.

The initial charge consists of charging the battery, with the power and light switch open, until each cell is bubbling freely from the top to bottom on the surface of the outside negative plates and both pilot balls are up (Delco-Light), and then CONTINUING THE CHARGE FOR FIVE HOURS MORE. If the battery has no pilot cells, measure the specific gravity of the electrolyte of each cell, and continue the charge until six consecutive readings show no increase in gravity.

As an accurate check on giving the initial charge properly (Delco-Light), we strongly recommend that hourly hydrometer readings of both pilot cells be taken after both balls are up, the charge to be continued until six consecutive hourly readings show no RISE in gravity.

Due to the fact that it is impossible to hold each cell in a battery to a definite maximum gravity when fully charged, there is likely to be a variation of from ten to fifteen points in the specific gravity readings of the various cells. It should be understood, however, that the maximum gravity is the gravity when the cells are fully charged and with the level of the solution at the water line. For example, with each cell in a battery fully charged and therefore at maximum gravity and with the level at the proper height, some cells may read 1.230, one or two 1.235, several 1.215 and 1.210. All of these cells will operate efficiently, and there should be no cause for alarm. An exception to this is the pilot cell of the Delco-Light Battery.

If this check on the initial charge is properly made, it assures the service man and dealer that the battery is in proper operating condition to be turned over to the user. Negligence in giving the initial charge properly may result in trouble to both user, service man and dealer.

The initial charge may require considerable running of the plant, depending upon the state of charge of the cells when installed.

Instructing Users

During the time the initial charge is being given, the service man should instruct the user on the care and operation of the plant and battery.

The best way to give instructions to the user is to tack the instruction cards on the wall near the plant in a place where the user can read them easily.

Proceed to read over the plant operating card with the user. Read the first item, go to the plant, explain this feature to the user and allow him to perform the operation, if the instruction calls for actual performance.

Remember, the user is not familiar with the plant and battery, and the actual performance of each operation aids him to retain the instructions.

After the first item has been covered thoroughly, proceed to the second, etc. During the course of instruction, the user will often interrupt with questions not dealing directly with the point being explained. The service man should keep the user's attention on the points he is explaining. When the service man has finished explaining both plant and battery instruction cards, he should answer any points in question which the user wants explained.

When the monthly equalizing charge is explained to the user, the service man should always take the user to the battery and show him a cell bubbling freely. This is necessary in order that the user may recognize when the cells are bubbling freely at the time he gives the monthly equalizing charge.

Impress upon the user the importance of inspecting each cell when giving the monthly equalizing charge to see that every cell bubbles freely. If a cell fails to bubble freely at the end of the equalizing charge, the user should inform the service man of this condition immediately.

Caution the user against the use of an open flame near the plant or battery at any time. The gas which accumulates in a cell will explode sufficiently to break the glass jar if this gas is ignited by a spark or open flame.

Care of the Plant in Operation

(See also special instructions for the different makes, beginning page 460.)

The battery repairman should be able not only to repair the batteries, but should also be able to keep the entire plant in working order, and suggestions will be given as to what must be done, although no detailed instructions for work on the generator, engine, and switchboard will be given as this is beyond the scope of this book.

Battery Room. The essential things about the battery room are that it must be clean, dry, and well ventilated. This means, of course, that the battery and battery rack must also be kept clean and dry. A good time to clean up is when the battery is being charged. Clean out the room first, sweeping out dirt and rubbish, dusting the walls, and so on. Both high and low temperatures should be avoided. If the battery room is kept too hot, the battery will become heated and the hot electrolyte will attack the plates and separators. Low temperatures do no actual harm to a charged battery except to make the battery sluggish, and seem to lack capacity. A discharged battery will, however, freeze above 0° Fahrenheit. The battery will give the best service if the battery room temperature is kept between 60° and 80° Fahrenheit.

Do not bring any open flame such as a lantern, candle or match near a battery and do not go near the battery with a lighted cigar, cigarette or pipe, especially while the battery is charging. Hydrogen and oxygen gases form a highly explosive mixture. An explosion will not only injure the battery, but will probably disfigure the one carrying the light, or even destroy his eyes.

It is a good plan to keep the windows of the battery room open as much as possible.

Engine. The engine which drives the generator requires attention occasionally. Wipe off all dirt, oil or grease. Keep the engine well lubricated with a good oil. If grease cups are used, give these several turns whenever the engine is run to charge the battery. Use clean fuel, straining it, if necessary, through a clean cloth or chamois, if there is any dirt in it. The cooling water should also be clean, and in winter a non-freezing preparation should be added to it. Do not change the carburetor setting whenever the engine does not act properly. First look over the ignition system and spark plug for trouble, and also make sure that the carburetor is receiving fuel. If possible, overhaul the engine once a year to clean out the carbon, tighten bearings and flywheel, remove leaky gaskets, and so on.

Generator. Keep the outside of the generator clean by wiping it occasionally with an oiled rag. See that there is enough lubricating oil in the bearings, but that there is not too much oil, especially in the bearing at the commutator end of the generator. Keep the commutator clean. If it is dirty, wipe it with a rag moistened slightly with kerosene. The brushes should be lifted from the commutator while this is being done. Finish with a dry cloth. If the commutator is rough it may be made smooth with fine sandpaper held against it while the generator is running, and the brushes are lifted.

The surfaces of the brushes that bear on the commutator should be inspected to see that they are clean, and that the entire surfaces make contact with the commutator. The parts that are making contact will look smooth and polished, while other parts will have a dull, rough appearance. If the brush contact surfaces are dirty or all parts do not touch the commutator, draw a piece of fine sandpaper back and forth under the brushes, one at a time, with the sanded side of the paper against the brush. This will clean the brushes and shape the contact surfaces to fit the curve of the commutator. Brushes should be discarded when they be come so short that they do not make good contact with the commutator. See that the brush holders and brush wires are all tight and clean. Watch for loose connections of wires, as these will cause voltage loss when the generator is charging the battery. Watch for "high mica," which means a condition in which the insulation between the segments projects above the surface of the commutator, due to the commutator wearing down faster than the insulation. If this condition arises, the mica should be cut down until it is slightly below the surface of the commutator. An old hack saw blade makes a good tool for this purpose. A commutator may have grooves cut in by the brushes. These grooves do no harm as long as the brushes have become worn to the exact shape of the grooves. When the brushes are "dressed" with sandpaper, however, they will not fit the grooves, and the commutator should be turned down in a lathe until the grooves are removed.

A steady low hum will be heard when the generator is in operation. Loud or unusual noises should be investigated, however, as a bearing may need oil, the armature may be rubbing on the field pole faces, and so on.

Watch for overheating of the generator. If you can hold your hand on the various parts of the generator, the temperature is safe. If the temperature is so high that parts may be barely touched with the hand, or if an odor of burned rubber is noticeable, the generator is being overheated, and the load on the generator should be reduced.

Switchboard. Clean off dirt and grease occasionally. Keep switch contacts clean and smooth. If a "cutout" is on the board, keep its contacts smooth and clean. If the knife switch blades are hard to move, look for cutting at the pivots. Something may be cutting into the blades. If this is found to be the case, use a file to remove all roughness from the parts of the pivot. See that no switches are bent or burned.

Keep the back of the board clean and dry as well as the front. See that all connections are tight. Keep all wires, rheostats, etc., perfectly clean. A coat of shellac on the wires, switch studs, etc., will be helpful in keeping these parts clean.

Care of Battery

Cleanliness. Keep the battery and battery rack clean. After a charge is completed, wipe off any electrolyte that may be running down the outsides of the jars. Wipe all electrolyte and other moisture from the battery rack. Occasionally go over the rack with a rag wet with ammonia or washing soda solution. Then finish with a dry cloth. Paint the rack with asphaltum paint once a year, or oftener if the paint is rubbed or scratched.

If sand trays are used, renew the sand whenever it becomes very wet with electrolyte. Keep the terminals and connectors clean. Near the end of a charge, feel each joint between cells for a poor connection. Watch also for corrosion on the connections. Corrosion is caused by the electrolyte attacking any exposed metals other than lead, near the battery, resulting in a grayish deposit on the connectors or bolts at the joints. Such joints will become hotter than other joints, and may thus be located by feeling the joints after the battery has been charged for some time. Corrosion may be removed by washing the part in a solution of baking soda.

Be very careful to keep out of the cells anything that does not belong there. Impurities injure a cell and may even ruin it. Do not let anything, especially metals, fall into a cell. If this is done accidentally, pour out the electrolyte immediately, put in new separators, wash the plates in water, fill with electrolyte having a gravity about 30 points higher than that which was poured out, and charge. The cell may be connected in its proper place and the entire battery charged. Vent plugs should be kept in place at all times, except when water is added to the electrolyte.

Keep the Electrolyte Above the Tops of the Plates. If the battery has glass jars, the height of the electrolyte can be seen easily. If the battery has sealed rubber jars, the height of the electrolyte may be determined with a glass tube, as described on page 55. In most batteries the electrolyte should stand from three-fourths of an inch to an inch above the plates. Some jars have a line or mark showing the proper height of the electrolyte. A good time to inspect the height of the electrolyte is just before putting the battery on charge. If the electrolyte is low, distilled water should be added to bring it up to the proper level. Water should never be added at any other time, as the charging current is required to mix the water thoroughly with the electrolyte.

Determining the Condition of the Cells. The specific gravity of the electrolyte is the best indicator of the condition of the battery as to charge, just as is the case in automobile batteries, and hence should be watched closely. It is not convenient or necessary to take gravity readings on every cell in the battery on every charge or discharge. Therefore, one cell called the "Pilot" cell should be selected near the center of the battery and its specific gravity readings taken to indicate the state of charge or discharge of the entire battery. Delco-Light batteries each have two pilot cells with special jars. Each of these has a pocket in one of its walls in which a ball operates as a hydrometer or battery gauge. One pilot cell contains the pilot ball for determining the end of the charge, and other pilot cell containing the ball for determining the end of the discharge. See Fig. 294.

Hydrometer readings should be taken frequently, and a record of consecutive readings kept. When the gravity drops to the lowest value allowable (1.150 to 1.180, depending on the make of battery) the battery should be charged.

Once every month voltage and gravity readings of every cell in the battery should be taken and recorded for future guidance. These readings should be taken after the monthly "overcharge" or "equalizing charge" which is explained later. If the monthly readings of any cell are always lower than that of other cells, it needs attention. The low readings may be due to electrolyte having been spilled and replaced with water, but in a farm lighting battery this is not very likely to happen. More probably the cell has too much sediment, or bad separators, and needs cleaning. See special instructions on Exide and Prest-O-Lite batteries which are given later.

There are several precautions that must be observed in taking gravity readings in order to obtain dependable results. Do not take gravity readings if:

(a) The cell is gassing violently.

(b) The hydrometer float does not ride freely. If a syringe hydrometer is used, the float must not be touching the walls of the tube, and the tube must not be so full that the top of the float projects into the rubber bulb at the upper end of the tube.

(c) Water has been added less than four hours before taking the readings. A good time to take readings is just before water is added.

The hydrometer which is used should have the specific gravity readings marked on it in figures, such as 1.180, 1.200, 1.220 and so on. Automobile battery hydrometers which are marked "Full," "Empty," "Charged," "Discharged," must not be used, since the specific gravities corresponding to these words are not the same in farm lighting batteries as in automobile batteries and the readings would be incorrect and misleading. If the manufacturer-of the battery furnishes a special hydrometer which is marked "Full," "Half-Full," "Empty," or in some similar manner, this hydrometer may, of course, be used.

Temperature corrections should be made in taking hydrometer readings, as described on page 65. For Prest-O-Lite batteries, 80 degrees is the standard temperature, and gravity readings on these batteries should be corrected to 80 degrees as described on page 461.

Gravity readings should, of course, be taken during charge as well as during discharge. The readings taken during charge are described in the following sections on charging.

Charging

(See also special instructions for the different makes, beginning page 460.)

Two kinds of charges should be given the battery, the "Regular" charge, and the "Overcharge" or "Equalizing Charge." These will be spoken of as the "Regular" charge and the "Overcharge." The Regular charge must be given whenever it is necessary in order to enable the battery to meet the lighting or other load demands made upon it. The overcharge, which is merely a continuation of a regular charge, should be given once every month. The overcharge is given to keep the battery in good condition, and to prevent the development of inequalities in condition of cells.

When to Charge. Experience will soon show how often you must give a regular charge in order to keep the lights from becoming dim. When the voltage reading, taken while all the lamps are on has dropped to 1.8 volts per cell a Regular charge is necessary. When the specific gravity of the pilot cell indicates that the battery is discharged, a Regular charge is necessary. It is better to use the specific gravity readings as a guide, as described later.

A good plan, and the best one, is to give a battery a Regular charge once every week, whether the battery becomes discharged in one week's time or not. A regular charge may be required oftener than once a week. Every fourth week give the Overcharge instead of the Regular charge.

If a battery is to be out of service, arrangements should be made to add the necessary water and give an overcharge every month, the Regular charges not being necessary when the battery stands absolutely idle.

Overcharge. Charge the battery as near as practicable at the rate prescribed by the manufacturer. If the manufacturer's rate is not known, then charge at a rate which will not allow the temperature of the electrolyte to rise above 110° Fahrenheit, and which will not cause gassing while the specific gravity is still considerably below its maximum value. One ampere per plate in each cell is a safe value of current to use. A battery having eleven plates in each cell should, for example, be charged at about 11 to 12 amperes.

Watch the temperature of the pilot cell carefully. This cell should have an accurate Fahrenheit thermometer suspended above it so that the bulb is immersed in the electrolyte. If this thermometer should show a temperature of 110°, stop the charge immediately, and do not start it again until the temperature has dropped to at least 90'. Feel the other cells with your hand occasionally, and if any cell is so hot that you cannot hold your hand on it measure its temperature with the thermometer to see whether it is near 110'. A good plan is to measure the temperature of the electrolyte in every cell during the charge. If any cell shows a higher temperature than that of the pilot cell, place the thermometer in the cell giving the higher reading, and be guided by the temperature of that cell. You will then know that the thermometer indicates the highest temperature in the entire battery, and that no other cell is dangerously hot when the thermometer does not read 100 degrees or over. Another point in the selection of a pilot cell is to determine if any particular cell shows a gravity which is slightly less than that of the other cells. If any such cell is found, use that cell as the pilot cell in taking gravity readings while the battery is on discharge and also on charge. No cell will then be discharged too far.

When all cells are gassing freely, continue the charge at the same current until there is no rise in the specific gravity of the pilot cell for one to two hours, and all cells are gassing freely throughout the hour. Then stop the charge.

After the overcharge is completed, take gravity readings of all the cells. A variation of about eight to ten points either above or below the fully charged gravity after correction for temperature does not mean that a cell requires any attention. If, however, one cell continually reads more than 10 points lower then the others, the whole battery may be given an overcharge until the gravity of the low cell comes up. If the cell then does not show any tendency to charge up properly, disconnect it from the battery while the battery is discharging and then connect it in again on the next charge. If this fails to bring the gravity of the cell up to normal, the cells should be examined for short circuits. Short circuits may be caused by broken separators permitting the active material to bridge between the plates; the sediment in the bottoms of the jars may have reached the plates, or conducting substances may have fallen in the cells.

Broken separators should be replaced without loss of time, and the cells cleaned if the sediment in the jars is high.

Regular Charge. A Regular Charge is made exactly like an Overcharge, except that a Regular Charge is stopped when cells are gassing freely, when the voltage per cell is about 2.6, and when the specific gravity of the pilot cell rises to within 5 points of what it was on the previous Overcharge. That is, if the gravity reading on the Overcharge rose to 1.210, the Regular Charge should be stopped when the gravity reaches 1.205.

## Partial or Rapid Charge. If there is not enough time to give the

battery a full Regular Charge, double the normal charging rate and charge until all the cells are gassing, and then reduce to the normal rate. Any current which does not cause excessive temperature or premature gassing is permissible, as previously mentioned. If a complete charge cannot be given, charge the battery as long as the available time allows, and complete the charge at the earliest possible opportunity.

Discharge

Do not allow the battery to discharge until the lights burn dim, or the voltage drops below 1.8 per cell. The specific gravity is a better guide than the lamps or voltage. The gravity falls as the battery discharges, and is therefore a good indicator of the condition of the battery. Voltage readings are good guides, but they must be taken while the battery is discharging at its normal rate. If the load on the battery is heavy, the voltage per cell might fall below 1.8 before the battery was discharged. Lamps will be dim if the load on the battery is heavy, especially if they are located far away from the battery. The specific gravity readings are therefore the best means of indicating when a battery is discharged.

Overdischarge. Be very careful not to discharge the battery beyond the safe limits. Batteries discharging at low rates are liable to be overdischarged before the voltage gives any indication of the discharged condition. This is another reason why hydrometer readings should be used as a guide.

A battery must be charged as soon as it becomes discharged. It is, in fact, a good plan, and one which will lengthen the life of the battery, to charge a battery when it is only about three fourths discharged, as indicated by the hydrometer. Suppose, for instance, that the specific gravity of the fully charged battery is 1.250, and the specific gravity when the battery is discharged is 1.180. This battery has a range of 1.250 minus 1.180, or 70 points between charge and discharge. This battery will give a longer life if its discharge is stopped and the battery is put on charge when the gravity falls to 1.200, a drop of 50 points instead of the allowable 70.

Allowing discharged battery to stand without charge. A battery should never be allowed to stand more than one day in a discharged condition. The battery will continue to discharge although no current is drawn from it, just as an automobile battery will. See page 89. The battery plates and separators will gradually become badly sulphated and it will be a difficult matter to charge the battery up to full capacity.

Battery Troubles

Farm lighting batteries are subject to the same general troubles that automobile batteries are, although they are not as likely to occur because the operating conditions are not as severe as is the case on the automobile. Being in plain view at all times, and not being charged and discharged irregularly, the farm lighting battery is not likely to give as much trouble as an automobile battery. Neglect, such as failure to keep the electrolyte up to the proper height, failure to charge as soon as the battery becomes discharged, overdischarging, allowing battery to become too hot or too cold, allowing impurities to get into the cells, will lead to the same troubles that the same treatment will cause in an automobile battery, and the descriptions of, and instructions for troubles in automobile batteries will apply in general to farm lighting batteries also.

When a battery has been giving trouble, and you are called: upon to diagnose and remedy that trouble, you should:

1. Get all the details as to the length of time the battery has been in service.

2. Find out what regular attention has been paid to its upkeep; whether it has been charged regularly and given an overcharge once a month; whether distilled water has been used in replacing evaporation of water from the electrolyte; whether impurities such as small nails, pieces of wire, etc., have ever fallen into any cell; whether battery has ever been allowed to stand in a discharged condition for one day or more; whether temperature has been allowed to rise above 110 deg. F. at any time; whether electrolyte has ever been frozen due to battery standing discharged in very cold weather.

3. Talk to the owner long enough to judge with what intelligence he has taken care of the battery. Doing this may, save you both time and subsequent embarrassment from a wrong diagnosis resulting from incomplete data.

4. After getting all the details that the owner can supply, you will probably know just about what the trouble is. Look over the cells carefully to determine their condition. If the jars are made of glass note the following:

(a) Height of sediment in each jar.

(b) Color of electrolyte. This should be clear and colorless. A decided color of any kind usually means that dirty or impure water has been added, or impurities have fallen into the cell. For discussion of impurities see page 76.

(c) Condition of plates. The same troubles should be looked for as in automobile batteries. See pages 339 to 346. An examination of the outside negatives is usually sufficient. The condition of the positives may also be determined if a flash light or other strong light is directed on the edges of the plates. Look for growths or "treeing" between plates.

(d) Condition of separators. See page 346.

If cells have sealed rubber jars, proceed as follows:

(a) Measure height of electrolyte above plates with glass tube, as in Fig. 30. If in any cell electrolyte is below tops of plates that cell is very likely the defective one, and should be filled with distilled water. If a considerable amount of water is required to fill the jar it is best to open the cell, as the plates have probably become damaged. If the jar is wet or the rack is acid eaten under the jar, the jar is cracked and must be replaced.

If you have not found the trouble, make the following tests, no matter whether glass or rubber jars are used:

(a) Measure specific gravity of each cell. If any cell is badly discharged it is probably short-circuited, or contains impurities and had better be opened for inspection.

(b) Turn on all the lamps and measure the voltage of each cell. If any cell shows a voltage much less than 1.8 it is short-circuited or contains impurities, and should be opened for inspection.

(c) Examine the connections between cells for looseness or corrosion; and examine the connections between the battery and the generator, going over cables, switches, rheostats, etc. Make sure that you have a complete and closed charging circuit between the generator and the battery.

(d) If cutout is used on the switchboard, see that its contact points are smooth and clean, and that they work freely.

(e) Run the generator to see if it builds up a voltage which is sufficient to charge the battery, about 42 volts for a 16 cell battery. If the generator is not working properly, examine it according to directions on page 451. Check up the field circuit of the generator to be sure that it is closed. A circuit-tester made of a buzzer and several dry cells, or a low voltage lamp and dry cells, or a hand magneto is convenient for use in testing circuits. Test armature windings and field coils for grounds.

By the foregoing methods you should be able to determine what is to be done. The following rules should also help:

Cleaning and renewal of electrolyte is necessary when:

(a) Sediment has risen to within one-half inch of the bottom of the plates.

(b) Much foreign material is floating in the electrolyte, or electrolyte is of a deep brown color.

Replacement of parts is necessary when

(a) Separators are cracked or warped. See page 346 for Separator troubles.

(b) Plates are defective. See rules on pages 339 to 346.

PREST-O-LITE FARM LIGHTING BATTERIES

[Fig. 300 Element from Prest-O-Light farm light cell]

The Prest-O-Lite battery which is designed for use in connection with farm lighting plants is known as the FPL type. Cells of 7, 9, 11, 13 and 15 plates are made, the number of plates being indicated by putting the figure in front of the type letters. A seven plate cell is thus designated as a 7 FPL cell, which has an 80 ampere hour capacity at the 8 hour continuous discharge rate.

The FPL cell, the construction of which is shown in Figs. 295, 300, 301, 302 and 303, has a sealed glass jar with a lead antimony cover. The cover construction is shown in detail in Figs. 301 and 302. Insulation between the posts and cover is provided by a hard rubber bushing, a hard rubber washer, and a soft rubber washer. The bushing is shaped like a "T" with a hole drilled in the stem. The stem of the bushing fits down into the post hole in the cover, the flange at the top testing on the raised portion of the cover around the post hole. The post has a shoulder a little less than halfway up from its lower end. Upon this shoulder is placed the hard rubber washer, and upon the hard rubber washer is placed the soft rubber washer. This assembly is fastened to the cover by the "peening" process used in Prest-O-Lite automobile batteries as described on page 386. This forces the soft rubber washer tightly against the cover so as to make a leak proof joint-between the bushing and cover. The ring of lead formed around the posts by the peening process supports the posts, plates, and separators, which therefore are suspended from the cell cover. The plate straps extend horizontally across the tops of the plates, and thus also act as "hold-downs" for the separators. The separators are held up by two rectangular rubber bridges which fit Mito slotted extension lugs cast into the lower corners of the outside negative plates. An outside negative having these extension lugs is shown in Figure 303.

[Fig. 301 Cover of Prest-O-Light farm lighting cell]

[Fig. 302 Parts of Prest-O-Light farm lighting cell: nut, stud, terminal, hard rubber bushing]

[Fig. 303a Parts of Prest-O-Light farming light cell: glass jar, rubber jar, rubber cell connector, glass cell connector]

[Fig. 303b Parts of Prest-O-Light farm lighting cell: positive plate and outside negative plate]

[Fig. 303c Parts of Prest-O-Light farm lighting cell: long lead jumper, jumper, separator, short lead jumper]

Specific Gravity of Electrolyte. The values of the specific gravity of Prest-O-Lite farm lighting batteries are as follows:

Battery fully charged reads 1.250 Battery three-fourths charged reads 1.230 Battery one-half charged reads 1.215 Battery one-fourth charged reads 1.200 Battery discharged completely reads 1.180

These readings are to be taken with the electrolyte at a temperature of 80° Fahrenheit. Readings taken at other temperatures should be converted to 80°. To convert readings at a lower temperature to the values they would have at 80°, subtract one point for every two and one-half degrees temperature difference. For example, suppose a cell reads 1.225 gravity at 60°. To find what the gravity would be if the temperature of the electrolyte were 80° divide the difference between 80° and 60° by 2-1/2, or 80° minus 60° divided by 21/2 equals 8. The gravity at 80° would therefore be 1.225 minus .008, or 1.217, which is the value of specific gravity to use. If the specific gravity is read at a higher temperature than 80°, divide the difference between 80° and the temperature at which the gravity reading was taken by 21/2, and add the result to the actual gravity reading obtained. If, for example, the gravity were 1.225 at 100°, the gravity at 80° would be 1.225 plus .008, or 1.233.

Charging Rates. The normal charging rate to be used in giving Prest-O-Lite batteries a regular charge or overcharge are as follows:

Battery Charging Rate ------- ------------- 5 F.P.L. 5.0 amps. 7 F.P.L. 7.5 amps. 9 F.P.L. 10.0 amps. 11 F.P.L. 12.5 amps. 13 F.P.L. 15.0 amps. 15 F.P.L. 17.5 amps.

Rebuilding Prest-O-Lite Farm Lighting Batteries

Opening the Cell.

1. Make sure that the cell is as fully charged as possible. Since it is not very convenient to charge a single cell, a good time to open a cell for cleaning and repairing is immediately after the battery has been given an overcharge. See page 455.

2. Disconnect the cell from the adjoining ones.

3. Heat a thin bladed putty knife and insert it under the edge of the lead-antimony cover to melt the sealing compound. Run the knife all round the cover, heating it again if it should become too cool to cut the compound readily.

4. Grasp the lead posts above the cover and lift up gradually. This will bring up the cover, plates, and separators.

5. Place the plates on a clean board for examination. Use the instructions given on pages 339 to 346. Do not keep the plates out of the electrolyte long enough to let them dry, and the negatives heat up. If you cannot examine the plates as soon as you have removed them immerse them in 1.250 acid contained in a lead or non-metallic vessel until you can examine them.

6. In renewing the electrolyte, pour in as much new 1.250 acid as there was old electrolyte in the jar. (It is assumed that the electrolyte was up to the lower ridge of the glass jar before the cell was opened.) The new electrolyte must not have a temperature above 100 degrees when it is poured into the jar.

7. The separators can be pulled out easily when the plates are laid on their sides. All that is necessary is to remove the small rubber bridge at the bottom corners of the plates. The separators can then be pulled out. If the old separators are to be used again brush off any material that may be adhering to them, and keep them wet with 1.250 acid until they are replaced between the plates. Any separators that show cracks or holes, or that split while being replaced between the plates should be thrown away and new ones used.

8. It is not necessary to remove the sediment from the bottom of the jar unless it is within one half inch of the bottom of the plates. If the sediment is to be removed, carefully pour off the clear electrolyte into a lead, hard rubber, or earthenware jar, if the electrolyte is to be used again.

9. If one or two of the plates in either positive or negative groups need to be replaced it is best to burn a new plate to the strap without removing the peened cover. This is done by blocking under the row of plate lugs with metal blocks after cutting off old plate and cleaning the surface of strap. Insert new plate, the lug of which has been cut about 1/4 inch short, to allow for new metal. Choosing small oblong iron blocks of suitable size, build a form about the plate lug which fits same well. Now with a torch and burning lead fuse the new plate onto the old strap. When cool remove and test joint by pulling and slightly twisting the plate at the same time.

Sometimes one group of a starting and lighting battery may be in sufficiently good condition to pay to combine it with a new group, but this condition will very rarely, if ever, be met in farm lighting cell service. We advise the replacement of the complete cell element if either group is worn out, for the cost of repairs and of new group will probably not be warranted by the short additional life which the remaining old group will give.

10. Putting Repaired Cell Back into Service. After having finished all necessary cleaning, replacement, or repairs, remove all old sealing material, return the element with attached lead cover to the cell jar. It is not necessary to reseal the cover to the jars this sealing is essential only for insurance against breakage or leakage in shipment.

Add through the vent plug opening sufficient cool acid of 1.250 Sp. Gr. to reestablish the proper electrolyte level, which means that the electrolyte is brought up to the lower moulded glass ridge near the top of jar.

Connect the cell with any other repaired cells and charge at normal rate already indicated under "charging rates" until dell voltage reads 2.5 or above, at 80°. The positive to cadmium voltage should be at least 0.10 volts less than cell voltage itself. When this condition is obtained cell may be replaced in operating circuit with others and should give satisfactory service.

EXIDE FARM LIGHTING BATTERIES.

Exide Farm lighting Batteries are made with sealed glass jars, open glass jars, and sealed rubber jars, each of which will be described.

Batteries with Sealed Glass Jars.

Two types with sealed glass jars are made, these being the Delco Light Type, and the Exide type.

1. Delco-Light Type. This type is shown in Fig. 294. The cell shown is a pilot cell, there being two of these in each battery as explained below.

These cells are made in two sizes, the KXG-7, 7 plate, 80 ampere hour cell, and the KXG-13, a 13 plate, 160 ampere hour cell. These cells are assembled into a 32 volt, 16 cell battery, or a 110 volt, 56 cell battery.

The plate groups are supported from the cover, the weight being carried by the wooden cover supports as shown in Fig. 294. The strap posts are threaded, and are clamped to the cover and supports by means of alloy nuts, just as is the case in Exide automobile batteries.

A hard rubber supporting rod or lock pin extending across the bottoms of the plates holds the separators in position and prevents the plates from flaring out at the bottom. A soft rubber bumper fastened on each end of the rod acts as a cushion to prevent jar breakage in shipping.

The hard rubber cover overlaps the flanged top of the jar, to which it is sealed with special compound.

Battery Gauges and Instruments for Testing.

Every set of Delco-Light batteries has either one or two cells equipped with a pilot ball. Such a cell is known as a PILOT CELL. Fig. 294.

Pilot Cells are used to indicate to the USER the approximate state of charge or discharge of the battery.

The pilot ball is a battery gauge which is UP or DOWN, depending upon the state of charge of the battery.

Very high temperature affects the operation of the pilot ball. This accounts for-the fact that occasionally a battery will be charged and the pilot ball will be at the bottom of the pocket. A few hours later, after the electrolyte has cooled, the pilot ball will rise to the top.

We urge that the user be made to feel that the pilot ball is an excellent gauge and a good signal to watch in connection with the care and operation of his Delco-Light plant and battery. (Further mention will be made of the pilot ball in connection with the subject of proper operation.)

It is necessary that the maximum specific gravity of pilot cells be as near 1.220 as possible. Any great variation higher or lower will affect the operation of the pilot balls. Therefore, every effort should be made to adjust the maximum specific gravity of pilot cells to 1.220 when placed in service.

Batteries equipped with one pilot cell contain a white pilot ball which will be up when the specific gravity of the electrolyte is approximately 1.185. This ball will drop DOWN when the specific gravity falls a little below 1.185.

In other words, the pilot ball will float at a specific gravity of 1:185 or higher, and will sink at a specific gravity lower than 1.185.

Therefore, when the pilot ball is UP, the battery is more than half charged. When the pilot ball is DOWN, the battery is more than half discharged.

Batteries equipped with two pilot cells have one cell which contains a white ball and the other cell a white ball with a blue band.

The plain white ball will be UP when the specific gravity is approximately 1.175. The blue band ball will be UP when the specific gravity is approximately 1.205.

When both balls are UP, the battery is charged. When DOWN, the battery is discharged. The blue band ball will drop soon after the battery starts on discharge, or, in other words, when the specific gravity falls below 1.205. The white ball will remain UP until the specific gravity falls below 1.175.

The Ampere-Hour Meter

The ampere-hour meter, Fig. 304, is an instrument for indicating to the user the state of charge of the battery at all times and serves to-stop the plant automatically so equipped, when the battery is charged. (Further mention will be made of the ampere hour meter on page 471.)

In order to check the speed of the ampere-hour meter, use the following rule: On charge, the armature disc should give 16 revolutions in 30 seconds, with a charging rate of 15 amperes; on discharge, the armature disc should give 20 revolutions in 30 seconds, with a discharging rate of 15 amperes.

[Fig. 304 Delco-Light Ampere-Hour Meter]

Hydrometers

The standard hydrometer for service men is known as the Type V-2B.

A special type hydrometer showing three colored bands in place of numbers has been designed for users.

The bands are red, green and black. When the hydrometer test shows the bottom of the red band in the electrolyte, the battery, whether in glass or rubber jar, is discharged. When the top of the green band is out of the electrolyte, the glass jar battery is charged. The top of the black band out of the electrolyte indicates the rubber jar battery is charged.

When and How to Charge Battery

Plants with Average Loads

Loads of legs than ten (10) amperes can be taken directly from the battery, until:

1. The large hand on the ampere-hour meter reaches 12, or

2. Both pilot balls are down, or

3. Hydrometer test shows bottom of red band in the electrolyte.

If any or all of the three gauges listed above show the battery discharged, the plant should be started and operated continuously until the battery is charged, as indicated by:

1. Ampere-hour meter hand at FULL, or

2. Both pilot balls UP, or

3. Hydrometer test shows top of FULL band out of electrolyte.

(NOTE: Any one or all of the above three items may indicate battery charged. Meter hand at FULL would necessitate both balls UP. If both balls are not up, set hand back and charge to bring them up; then set hand at FULL.)

Should the user be operating for two or three hours with a seven or eight-ampere load, it would be more efficient to run the plant to carry this load. This only applies for those cases where the battery is partly discharged.

Carry Heavy Loads Greater Than 10 Amperes.

If there is a constant load of 10 amperes or more, the plant should be started up when the heavy load comes on. When the heavy load is off, the plant may be stopped, but it would be entirely satisfactory to allow the plant to continue to run until "Charged," as indicated by:

1. Ampere-hour meter hand reaches FULL, or

2. Both pilot balls are UP, or

3. Hydrometer test shows top of FULL band out of electrolyte.

In any case, plant should be run until battery is "Charged" at least once a week.

Always Start Charging When Battery Gauges Indicate Battery Discharged.

On ampere-hour meter plants, when the hand is at FULL, the plant cannot be operated on account of the ignition circuit being broken.

In such cases allow load to be taken from the battery until the hand travels back sufficiently to allow the plant to run.

Occasionally the plant and battery are used to carry continuous loads of from 10 to 15 amperes each night, with practically no day load. This condition necessitates running the plant to carry the load, but at the same time the battery is continually receiving from 10 to 15 amperes charge, with the result that the battery may receive too much charging. This would be indicated by the battery bubbling freely every time the plant is operated. To prevent this condition, the user should be instructed to carry the load off the battery frequently enough to prevent continual bubbling.

Where Small Load Is Used.

There are many installations where the battery capacity is sufficient to last several weeks. On installations of this kind it is advisable to charge the battery to FULL at least once a week.

The dealer or service man should use his own judgment on the preceding instructions as to which is best suited for the different conditions encountered.

Regularly on the first of each month, regardless of whether or not the battery has been used, a special charge, called the Equalizing Charge, should be given. This charge should be given as follows: The battery should be charged until EACH cell is bubbling freely from top to bottom on surface of the outside negative plates and then the charge should be continued for TWO MORE HOURS.

The monthly equalizing charge is a NECESSARY precautionary measure to insure that the user will bring each cell in the battery up to maximum gravity at least once a month. It also provides a means on the ampere-hour meter plants to set the ampere-hour meter hand at FULL when the battery is FULL.

The users should be cautioned to inform the service man or dealer immediately if any cell fails to bubble at the end of an equalizing charge, when all others are bubbling freely. This will enable the service man to inspect such cells for trouble and remedy same before the trouble becomes serious. (See further information under inspection and repairs.)

INSPECTION TRIPS

Undercharging or injurious sulphation is the most common trouble encountered. Undercharging causes the plates to blister and bulge, and in place of good gray edges on the negative plates and good brown color edges on the positive plates, the edges will show a faded color, with very little brown color showing on the edges of the positive plates.

Overcharging is not so evident on inspection, except that in such cases the active material from the positive plates, which is brown in color, will be thrown to the bottom as sediment more rapidly than the sediment would accumulate due to normal wear.

Heavy usage on a battery will also cause considerable sediment in the bottom of the cells, so that it is necessary to investigate carefully whether it is overcharging or overwork. A few questions as to method of operation and load requirements will aid in deciding the cause of excessive sediment. (See When and How to Charge, page 468.)

Sediment Space Filled.

When the space below the plates is filled up with sediment and touching the plates, the cell becomes short-circuited and will deteriorate very rapidly. It will be noticed, however, that the sediment is heaped in the middle of the cell. If the cells are unbolted and unshaken, it will level the sediment and leave a space between the sediment and plates. It is very important that the sediment be shaken down before the cell becomes short-circuited. This will very often prolong the life of the battery a number of months. When the sediment space is completely filled, approximately all the

## active material will be out of the positive plates.

A thorough study should be made as to the general condition of the battery and method of operation before forming an opinion or suggesting any change in method of operation.

Check Ampere-Hour Meters

On plants which have ampere-hour meters, the meter should be checked as to its speed on discharge, and also check position of the meter hand at the time of inspection, to see if it checks with the specific gravity and the pilot balls. (See Ampere Hour Meter, page 467.)

It will generally be found that when a battery is sulphated, it is operating in very low specific gravity, or, in other words, the charges have not been carried far enough to drive all the acid out of the plates.

A battery that is not receiving quite enough charge may not as a whole become "sulphated," but several cells might become considerably weaker than the others and become "sulphated," causing trouble in these

## particular cells. Such cells will not bubble freely, or possibly not

at all, when the other cells are bubbling freely. Therefore, a few questions to the user will generally help in locating the low cells.

Cells that are in trouble, or which soon will be, can very easily be picked out by making a few tests on the battery. Therefore, on all inspections, regardless of the age of a battery, it is suggested that the following tests be made: Take a specific gravity reading of all cells and note if there are any cells much lower than the others. Amy cells having a specific gravity of 30 points lower than the average will generally be found to be in trouble, unless these cells happen to be low from having had spillage in shipment, replaced with water. (This condition, however, should not exist in future installations if the spillage is properly taken care of, as has been explained on page 482.)

Voltage Readings

After taking a specific gravity reading, a voltage reading of each cell should be taken. Voltage readings taken on open circuit are of no value, so while taking these readings the battery should be on discharge, having at least a discharge of 15 amperes. A good way to get this discharge is to hold the starting switch in and set mixing valve lever at lean point or wide open.

A low or defective cell will show a voltage reading .10 to .20 volts lower than the other cells on discharge, while a reversed cell will show a reading in the reversed direction when on discharge, especially on heavy discharge.

The voltage readings are a sure check if taken in connection with the specific gravity. When you have low specific gravity and low voltage on the same cells, it is a sure indication of low cells. These cells should be inspected for the probable cause of their being low. Shorting of the lugs at bottom of plates and moss bridging across at bottom of the elements, or possibly a split separator, will generally be the main trouble.

When any of these conditions exist, it is best to take the low cells back to your shop for repairs.

When there is absolutely no indication why the cells are low, they can be cut out of the battery on discharge and put in on charge, until they come up.

The following is a good example of readings taken on a battery with a 10-ampere discharge and having four low cells, 4, 8, 11 and 16. The battery had been giving poor service, due to insufficient charging:

Cell No. Specific Gravity Volts 1 1.200 1.98 2 1.180 1.95 3 1.205 1.98 4 1.150 1.75 5 1.190 1.95 6 1.195 1.98 7 1.200 1.98 8 1.130 1.70 9 1.200 1.95 10 1.205 1.98 11 1.100 1.40 12 1.190 1.95 13 1.180 1.95 14 1.195 1.98 15 1.190 1.95 16 0.000 zero or reversal

The main thing to consider in checking voltage readings is the variation from the average. The average voltage readings will vary, depending on the state of charge of the battery when the readings are taken.

REPAIRS

To repair, the following equipment is necessary:

1. Portable lead burning outfit. 2. A suitable blow torch. 3. Standard sealing nut wrench. 4. File (shoemaker's rasp). 5. Pair of pliers. 6. Putty knife. 7. Pair of tin snips. 8. Wooden blocks to support elements while being worked upon. 9. Good supply of battery parts consisting of: KXG-13 Glass jars KXG-13 Pilot jars KXG-13 Positive groups KXG-13 Negative groups KXG-13 Round rods KXG-13 Vent plugs Sealing nuts Rubber gaskets Wood separators KXG-13 Rubber covers KXG-7 Round rods Lead pins Carboy electrolyte (including retainer). KXG-7 Pilot jars KXG-7 Glass jars KXG-7 Positive groups KXG-7 Negative groups Outside negative plates KXG-7 Rubber covers Emergency repair straps

Disassembling a Cell

The glass jar battery covers are sealed to the jars by sealing compound, which may be softened very easily with a blow-torch.

When a blow-torch or an open flame is used for softening the sealing compound, the vent plug MUST be removed before applying a flame. It is also important to blow into the vent after the plug has been removed in order to expel any gas that may have collected in the space above the electrolyte in the cell.

If the gas is held in place by leaving the vent plug in, it is apt to explode when an open flame or intense heat is applied to the cover.,

Removing covers may be greatly facilitated by suspending the cell by the terminals, as shown in Fig. 305. Care should be taken to make this suspension so that the bottom of the jar will not be more than two inches above the table. A pad of excelsior should be placed under it to avoid breaking the glass jar when it drops.

[Fig. 305 Softening sealing compound, Delco-Light cell]

After the sealing compound has been sufficiently softened, the cover may be loosened by inserting a hot putty knife, as shown in Fig. 306, There is no danger of breaking the cover by this operation if the cover has been sufficiently warmed. After the jar of electrolyte has dropped, the element should be removed from the jar and carefully placed across the top of it, so that the solution upon the plates will drain back into the jar. (See Fig. 307.)

[Fig. 306 Removing Delco-Light cell cover]

[Fig. 307 Draining element, Delco-Light cell]

[Fig. 308 Removing cover of Delco-Light cell]

[Fig. 309 Removing lock pin, Delco-Light cell]

After element has drained, place on wooden blocks, as shown in Fig. 308, and remove cover. Clean the sealing compound from the cover and jar immediately with a putty knife. Turn element upside down with posts through holes in bench and remove lead pin and rubber bumper and withdraw, lock pin. (Fig. 309.) The separators may then be withdrawn from the group. (Fig. 310.)

[Fig. 310 Removing separatots, Delco-Light cell]

[Fig. 311 Assembling separators, Delco-Light cell]

Assembling

Place the positive and negative groups upside down with posts through holes in bench and slide in separators. The wood and rubber separators are inserted as follows: The rubber separator is placed against the grooved side of the wood separator, and the two are then slipped between the negative and positive plates with the rubber separator next to the positive plate. (See Fig. 311.)

Inserting Locking Pin

A rubber bumper is pinned on one end of the lock pin by means of a lead pin, and the lock pin is then slipped into place with the lock pin insulating washer placed between the outside negative plates and the wood separators. (See Fig. 312.)

A rubber bumper is then slipped over the other end of the lock pin and secured by a lead pin.

Place element on wooden blocks and fasten cover, as shown in Fig. 313.

[Fig. 313 Fastening cover, Delco-Light cell]

[Fig. 314 Preparing cover for sealing, Delco-Light cell]

Sealing Covers

Be sure all old sealing compound and traces of electrolyte are removed from the cover. Heat sealing compound until it can be handled like putty, roll out into a strip about 1/2 inch in diameter, place strip of compound around inside edge of cover (Fig. 314) and heat to melting point with blow-torch. The top of jar should also be heated to insure a tight seal. Compound can be melted in a suitable vessel and a 1/2 inch strip poured around cover.

When sealing compound and jar have been heated sufficiently, turn jar upside down (Fig. 315) and carefully place jar over element and press gently into compound. (Do not press hard.) Immediately place jar and element upright, and press cover firmly into place. (Press hard.) Finally, tighten sealing nuts. The cell is now ready for the electrolyte.

[Fig. 315 Sealing jar of Delco-Light cell]

Filling Cell with Electrolyte

Repaired cells should be filled with electrolyte of 1.200 specific gravity, or with water, as the case may require.

Standard Delco-Light electrolyte of 1.220 specific gravity may be purchased from the Delco Light distributor. The 1.220 electrolyte should be reduced to 1.200 by adding a very small amount of distilled water. This should be thoroughly mixed by pouring the solution from one battery jar into another. The 1.200 specific gravity electrolyte may then be added to the newly assembled cell until flush with the water line.

Charging

The completed KXG-13 cell should be placed on a 12-ampere charge and kept on charge until maximum gravity has been reached. A KXG-7 cell should be charged at a 6-ampere rate.

Adjusting Gravity of Electrolyte

If the maximum gravity is above 1.220, draw off some of the electrolyte and refill to water line with distilled water. The charge should then be continued for at least one hour to thoroughly mix the electrolyte before taking another hydrometer reading. It may be necessary to repeat this operation.

If the maximum gravity is below 1.220, pour off the electrolyte into a glass jar or a suitable receptacle, and then refill the cell with 1.220 electrolyte. Charge for one hour to thoroughly mix the solution before checking readings.

NOTE: Gravity readings in adjusting the electrolyte should always be taken in connection with thermometer readings, making necessary temperature corrections. This is particularly important in adjusting electrolyte in pilot cells.

HOW TO REPAIR DELCO-LIGHT CELLS

Treating Broken Cells

Whenever a shipment of batteries is received in which any of the jars have been broken, the first thing to do is to carefully remove the elements from the broken jars to prevent damage to the plates or separators. These elements should be placed in distilled water to prevent further drying. The plates will not be damaged in any way and can be restored to a healthy condition by charging in 1.200 specific gravity at a 12-ampere rate for the 13-plate cell or, 6-ampere rate for the 7-plate cell, until maximum gravity is reached. (See Charging and Adjustment of Electrolyte, explained on page 481.)

Treating Spilled Cells

If the spillage is more than one inch below the water level, it should be replaced by electrolyte of 1.200 specific gravity and charged to maximum gravity.

Treating Badly Sulphated Cells That Have Been in Service

When cells are removed from an installation to make repairs, they are usually badly sulphated, which means that considerable acid is in the plates.

In charging such cells, use distilled water in place of electrolyte, as this will allow the acid to come out of the plates more readily. The KXG-13 cells should be charged at about 12 amperes and the KXG-7 cells at 6 amperes. Cells badly sulphated when charged at the low rate will require from 50 to 100 hours to reach maximum gravity. Extreme cases will require even longer charging.

In case it is impossible to read the gravity after the cells have been on charge a sufficient length of time, pour out the solution and use 1.220 specific gravity.

The charge should then be continued further to insure that maximum gravity has been reached.

CAUTION: Should the temperature of the electrolyte approach 110° F., the charging rate should be reduced or the charge stopped until the cell has cooled.

Treating Reversed Cells

A complete battery may be reversed if the battery is completely discharged and its voltage is not sufficient to overcome any residual magnetism the generator might have. Under such conditions the negative plates will begin to discolor brown and the positive turn gray. Such a case would be extremely rare.

The remedy is to first completely discharge the cells to get rid of the charge in the wrong direction. Then short-circuit them. (Connect a wire across the terminals.) Then charge them in the right direction at a low rate. (12 amperes for a KXG-13 cell, or 6 amperes for a KXG-7 cell.) Charge until the specific gravity reaches a maximum. If the battery is operated reversed for any length of time, the negatives will throw off their active material and become useless.

A single cell may become reversed by gradually slipping behind the rest of the cells in a set, due to insufficient charging, until it becomes so low that it will reverse on each discharge. This condition cannot be corrected by giving the regular charge, but it will be necessary to give an equalizing charge, continuing the charge until the cell is in normal condition. (Be sure to make temperature corrections when taking hydrometer readings.) If the cell appears to require an excessive amount of charge to restore it to condition, it should be removed and taken to the repair shop for a separate charge.

If the cell has been allowed to operate in a reversed condition to such an extent that the entire material of the negative plates has turned brown, both positive and negative groups should be discarded.

Removing Impurities

Impurities, such as iron, salt (chlorine) or oil, may accidentally get into a cell, due to careless handling of distilled water.

Iron is dissolved by sulphuric acid and the positive plates become affected, change color (dirty yellow) and wear rapidly. The cell becomes different from the rest in gravity, voltage and bubbling. The remedy is to discard the electrolyte as soon as possible, flush the plates and separators in several changes of water, thoroughly wash the jar, use new electrolyte and then proceed in same manner as explained for the treatment of badly sulphated cells, page 482.

Chlorine has an effect about as described for iron, and is evident by the odor of chlorine gas. The remedy is the same as for iron.

Oil in the electrolyte, if allowed to get into the pores of the plates, will fill them and lower the capacity very much. It affects negative plates much more than positives. Probably the only remedy in this case is new plates.

Impurities of any nature should be removed as quickly as possible.

Clearing High Resistance Short Circuits

A high resistance short is caused by the sediment falling from the plates and lodging between the positive and negative lugs. As a rule this condition will occur only when severe sulphation is present in the plates.

A cell in this condition can be repaired by removing the element and clearing the short circuit. The wood separators should then be withdrawn and replaced by new ones. Lock pin insulating washers. should be installed land the element reassembled in the jar and charged to maximum gravity.

Clearing Lug Shorts

Short-circuited lugs are caused by excessive sulphation. The outside negative bulges and the bottom lug bends over and touches the adjacent positive lug. This can be remedied by removing both outside negative plates and burning on new plates which have already been charged and inserting lock pin insulating washers.

Putting Repaired Cells Back in Service

When placing a new or repaired cell in a battery which is in service, connect in the cell at the beginning of a charge. This will insure that the new or repaired cell is started off in good condition, because this charge is of the nature of an initial charge to these cells.

Charging Outside Negative Plates

Individual negative plates are always received dry, which makes it necessary to charge them before using. The best way to charge such plates is as follows: Set up 7 loose negative plates in a KXG-13 jar together with a good positive group, using KXG separators to prevent the plates touching. Then stretch a piece of wire solder across the lugs at the top of the negative plates and solder the wire to the plates. Fig. 316. The jar may then be filled with 1200 specific gravity and the plates charged at a 12-ampere rate until maximum gravity is obtained. Never use negative plates unless they have been treated as described above. After the charge is completed, the negative plates may be placed in distilled water and kept until ready for use. Always be sure to give a charge to maximum gravity after burning on new negative plates to an element.

[Fig. 316 Preparing outside negatives for charging]

Pressing Negative Plates

After badly sulphated cells are recharged, it is sometimes advisable to remove the elements and, press the negative plates, as explained on page 351. Care should be taken to prevent the negative plates from drying out while making repairs, in order to avoid the long charge necessary for dried negative plates.

The battery should be charged to maximum gravity before attempting to press the plates.

It is not necessary and will do no good to press the positive plates.

In some cases the active material may be nearly all out of the outside negative plates and the inside negatives may be in good condition, in which case new charged plates should be burned on. (Fig. 322.)

Salvaging Replaced Cells

When it has been necessary to replace cells which have been in service, the elements can very often be saved and assembled again and used as replacement cells in batteries which are several years old. In no case should the cells be used as new cells.

The positive plates may be allowed to dry out, but the negatives should be kept in distilled water and not allowed to dry out in the least. They should not be kept this way indefinitely, but should be assembled and charged as soon as possible.

Do not attempt to repair groups or plates which have lost as much as half of the active material in wear, or which have the active material disintegrated and falling out. Such plates should not be used. This does not apply to small bits of active material knocked out mechanically and amounting to an extremely small percentage of the whole. Abnormal color indicates possible impurity, and such plates should be washed and used with caution. Badly cracked or broken plates should be replaced with new plates or plates from other groups.

Before new negative plates are used they should be fully charged. (See Charging Negative Plates, page 484.)

Always use new wood separators when assembling repaired cells.

When cells have been operated reversed in polarity to such an extent that the active material of the negative plates has turned brown, both positive and negative groups may have to be replaced.

Repairing Lead Parts

The portable carbon burning outfit used for battery repairs is operated from the battery itself, making it possible to make repairs at the user's residence without using a gas flame.

This outfit can be secured from the Delco-Light Company, Dayton, Ohio, and consists of a carbon holder with cable, clamp, and one-fourth inch carbon rods. Six cells are usually required to properly heat the carbon. If it is completely discharged an outside source must be used. For this purpose a six-volt automobile battery is suitable, or a tray of demonstrating batteries, one terminal being connected to the connection to be burned, the other to the cable of the burning tool. A little experience will soon demonstrate the number of cells necessary to give a satisfactory heat. The cable is connected by means of the clamp to a cell in the battery, the required number of cells away from the joint to be burned. Care should be taken that contact is made by the clamp, the lead being scraped clean before the connection is made. The carbon should be sharpened to a long point like a lead pencil and should project not more than 2 inches from the holder. (Fig. 317.)

[Fig. 317 Repairing broken post, Delco-Light cell]

After being used a short time, the carbon will not heat properly, due to a film of scale formed on the surface. This should be cleaned off with a file.

In case of lead burning, additional lead to make a flush joint should not be added until the metal of the pieces to be joined has melted. The carbon should be moved around to insure a solid joint at all points.

In case a post is broken off under the cover, proceed as follows: To make repairs take an old group and cut off the post about one-half way down. Saw off the post to be repaired to such a length that when the new post is burned on the length of the post will be approximately the same length as the original post.

Repairing Broken Posts.

Make a half circle mould out of a piece of tin or galvanized iron, as shown in Fig. 317. Burn solid the side of the post facing up, file it around and then turn the group over, place the form on the burned side and proceed to complete the burning operation.

Caution:

1. Always use clean lead.

2. Do not clean the lead and let it stand for any length of time before starting to burn. If it is allowed to stand it will oxidize and prevent a good burning operation.

3. Burn with an are and not with a red hot carbon.

Burning on Straps

Place the strap to be burned in a vise and split the end through the center and then bend the two halves over to form a foot, as shown in Fig. 318. Make a mould out of a piece of tin or galvanized iron and place this mould around the post to which this strap is to be burned. (Fig. 319.) Then proceed to burn the post and strap together.

[Fig. 318 Splitting end of strap, Delco-Light cell]

When a union is made between the strap and the post a small amount of new clean lead should be burned on the top of the foot to reinforce this point. Care should be taken not to get the mould too high, as this will cause trouble in getting the carbon down to the foot and the post.

[Fig. 319 Burning on negative strap, Delco-Light cell]

[Fig. 320 Auxiliary strap, Delco-Light cell]

[Fig. 321 Positioning auxiliary strap, Delco-Light cell]

How to Eliminate Burning on Straps by Use of an Auxiliary Strap

A very good way to repair broken straps without the burning operation is to use the auxiliary strap shown in Fig. 320. This strap is slipped over the post of the terminal or strap which is broken and the sealing nut is then clamped down on the strap, as shown in Fig. 321. These straps may be obtained from the Delco-Light Distributors or from the Delco-Light factory at Dayton, Ohio.

Burning on New Plates

[Fig. 322 Burning on outside negative plate, Delco-Light cell]

When it is necessary to burn on new plates, carefully clean with a file the lead on both the plate and the common strap to which all plates of the group are attached. Block up the plate with thin boards or wood separators until it is spaced the proper distance from the adjacent plate. Care should be taken to see that the side and bottom edge of the plate to be burned on is in line with the other plates of the group. Proceed to burn on the plate by drawing a small blaze or are and do not attempt to burn with just a glowing carbon. (Fig. 322.)

If only a glowing carbon is used the result will be a smeary mass and in the majority of cases will not hold, due to the fact that it is not welded but simply attached in one or two points.

The principle of lead burning is to weld or burn two parts into one solid mass and not merely attach one to the other.

Keeping Wood Separators In Stock

No wood separators should be used except those furnished by the Delco-Light Company. These should be kept in distilled water, to which has been added 1.220 electrolyte in the proportion of one part to ten parts of water. It is advisable whenever possible to use new separators when making repairs on a cell. Separators which have been in service are liable to be damaged by handling.

Freezing Temperature of Electrolyte

The freezing temperatures of electrolyte in the Delco-Light batteries depends upon the specific gravity of the battery. The Delco-Light battery fully charged, with a specific gravity of 1.220, should not freeze above a temperature of 30 degrees below zero. Since, however, the freezing point rises very rapidly with a decrease in specific gravity, special care should be taken to keep batteries charged when temperatures below zero are encountered. The following table shows freezing temperatures of several different gravities of electrolyte.

Specific Gravity Freezing Point ---------------- -------------- 1.100 19° F. above zero. 1.150 5° F. above zero. 1.175 6° F. below zero. 1.200 16° F. below zero. 1.220 31° F. below zero.

At the temperature given, the electrolyte does not freeze solid, but forms a slushy mass of crystals, which does not always result in jar breakage.

Care of Cells in Stock

Frequently a Dealer or Distributor will have several sets of new batteries in stock for five or six months. In this case, the cells should be given a freshening charge before putting into service. This charge should consist of charging the cells to maximum gravity.

Cells received broken in transit or cells sent in for repairs should be repaired and charged as soon as possible and put into service immediately. This eliminates the possibility of the cells standing idle over a long period in which they would need a freshening charge before they could be used.

However, if such cells must be kept in stock, they can be maintained in a healthy condition by keeping on charge at a one fifth ampere rate for 13-plate cells and one-tenth ampere rate for 7-plate cells.

Taking Batteries Out of Commission

If a battery is not to be used at all for a period not longer than about 9 months, it can be left idle if it is first treated as follows: Add sufficient water to bring the electrolyte up to the water line in all cells and then give an equalizing charge, continuing the charge until the specific gravity of each cell is at a maximum, five consecutive hourly readings showing no rise in gravity. As soon as this charge is completed, take out the battery fuse and open up one or two of the connections between cells so that no current can be taken from the battery. Have vent plugs in place to minimize evaporation.

If the battery is to be taken out of commission for a longer time than 9 months, the battery should be fully charged as above and the electrolyte poured off into suitable glass or porcelain receptacles. The plates should immediately be covered with water for a few hours to prevent the negatives heating, after which the separators should be removed, the water poured out of the jars, and the positive and negative groups placed back in the jar for storage. Examine the separators. If they are cracked or split they should be thrown away. If in good condition they should be stored for further use in a non-metallic receptacle and covered with water, to which has been added electrolyte of 1.220 specific gravity, in the proportion of one part electrolyte to ten of water by volume.

Putting Batteries Into Commission After Being Out of Service

When putting batteries into commission again, if the electrolyte has not been withdrawn, all that is necessary is to add water to the cells if needed, replace connections, and give an equalizing charge.

If the electrolyte has been withdrawn and battery disassembled, it should be reassembled, taking care not to use cracked, split or dried-out separators, and then the cells should be filled with the old electrolyte, which has been saved, provided no impurity has entered the electrolyte. After filling, allow the battery to stand for 12 hours and then charge, using 6 amperes for KXG-7 size and 12 amperes for the KXG-13 size. Charge at this rate until all cells start gassing freely or temperature rises to 110° F. Then reduce the charging rate one-half, and continue at this rate until the specific gravity is at a maximum, five consecutive hourly readings showing no rise in gravity. At least 40 hours will be required for this charge. To obtain these low rates with the Delco-Light plant, lights or other current-consuming devices must be turned on while charging.

General Complaints from Users and How to Handle Them.

1. Pilot balls do not come up.

This condition may be caused by

(a) Battery discharged. (b) Weak electrolyte caused by spillage in shipment. (c) Defective ball.

Question the user to determine whether the ball will not come up if the pilot cell is bubbling freely. Weak electrolyte or a defective ball will require a service trip to determine the one which is responsible for the ball not rising. (See page 470.)

2. Lights dim-must charge daily.

This condition may be caused by

(a) Discharged battery. (b) Loose dirty connections in battery or line. (c) Low cells in battery.

The user should be questioned to determine whether the battery is being charged sufficiently. In case the user is positive the battery is charged, the next probable trouble would be that there were some loose or dirty connections in either plant or battery. Have the user check for loose connections. Should it be necessary to make an inspection trip, instruct the user to give battery an equalizing charge so the battery will be fully charged when the inspection is made.

Low cells can be checked by asking the user if all of the cells bubble freely when equalizing charge is given. In case user claims several cells fail to bubble, an inspection trip would be necessary to determine the trouble. (See page 470.)

3. Cells bubbling when on discharge.

This complaint would indicate a reversed cell. (See page 483.)

4. Cells overflowing on charge.

This would mean that the cells were filled too high above water lines.

5. Engine cranks slowly but does not fire.

This would indicate over-discharged battery. Explain to user how to start plant under this condition.

6. Plant will not crank.

This might be caused by

(a) Blown battery fuse. (b) Battery over-discharged. (c) Loose or broken connection on battery or switchboard.

OTHER EXIDE FARM LIGHTING BATTERIES

The Exide type is shown in Figure 296. The plates are held in position both by the cover and by soft rubber support pieces in the bottom of the jar. The support pieces are provided with holes in which projections on the bottom of the plates are inserted. The cover is of heavy moulded glass. The separators are of grooved wood in combination with a slotted rubber sheet (Fig. 297). The strap posts are threaded and are clamped to the cover by means of alloy nuts. The cover overlaps the top of the jar to which it is sealed with sealing compound. The method of sealing and unsealing is practically the same as in the Exide Delco-Light Type.

Batteries with Open Glass Jars

Batteries with open glass jars, in addition to the conducting lug, have two hanging lugs for each plate. The plates are hung from the jar walls by these hanging lugs, as shown in Figs. 323 and 324. The plate straps, instead of being horizontal are vertical and provided with a tail so that adjacent cells may be bolted together by bolt connectors through the end of the tail.

1. The Exide Cell is shown in Fig. 324. It has a grooved wood separator between each positive and negative plate. The separators are kept from floating up by a glass "hold-down" laid across the top. The separators are provided at the top with a pin which rests on the adjoining plates. The pins together with the plate glass hold-downs keep the separators in Position.

To remove an element it is simply necessary to unbolt the connectors, remove the glass cover and hold-down and lift wit the element.

2. The Chloride Accumulator cell is shown in Fig. 323. It differs from the Exide only in type of plates and separators. The positive plates are known as Manchester positives and have the active material in the form of corrugated buttons which are held in a thick grid, as shown in Fig. 325. The buttons are brown in color, the same as all positive

## active material.

The separators, instead of being grooved wood, am each a sheet of wood with six dowels pinned to it.

The element is removed the same as in the Exide type.

[Fig. 323 Exide chloride accumulator cell with open glass jar, and Fig. 324 Exide cell with open glass jar]

Batteries with Sealed Rubber Jars

1. The Exide cell is shown in Fig. 326. It is assembled similar to Exide starting and lighting batteries, except that the plates are considerably thicker, wood and rubber separators are used, and the terminal posts are shaped to provide for bolted instead of burned-on connection. The method of sealing and unsealing the cells is the same as in Exide starting and lighting batteries.

All instructions already given for glass for cells apply to rubber jar cells except for a few differences in assembling and disassembling.

Care should be taken to keep the water level at least 1/2 inch above plates at all times as the evaporation is very rapid in rubber jar cells.

The temperature should be watched on charging to prevent overheating. Never allow temperature to go above 110° F.

Unlike the glass jar cells the sediment space in the rubber jar is not sufficient to take care of all the active material in the positive plates. On repairs, therefore, always clean out the sediment and prevent premature short circuits.

[Fig. 325 Manchester positive plates, and Fig. 326 Exide cell with sealed rubber jar]

WESTINGHOUSE FARM LIGHTING BATTERIES

Jars. Westinghouse Farm Lighting Battery jars are made of glass, with a 5/16 inch wall. The jars are pressed with the supporting ribs for the elements an integral part from a mass of molten glass. A heavy flange is pressed around the upper edge to strengthen the jar.

Top Construction. A sealed-in cover is used similar to that used in starting and lighting batteries. The opening around the post hole is sealed with compound.

Plates. Pasted plates are used. The positives are 1/4 inch thick, and the negatives 3/16 inch. Posts are 13/16 inch in diameter.

Separators. A combination of wood and perforated rubber sheets is used.

Opening and Setting-Up Westinghouse Farm Lighting Batteries

[Fig. 327 Westinghouse farm lighting cell]

It is preferable that the temperature never exceed 100 deg. Fahrenheit nor fall below 10 deg. in the place where the battery is set up. If the temperature is liable to drop below 10 degrees the battery should be kept in a fully charged condition.

1. Remove all excelsior and the other packing material from the top of the cells. Take cells out carefully and set on the floor. Do not drop or handle roughly. Be sure to remove the lead top connectors from each compartment.

2. Cells should be placed 1/4 inch apart. Also, cells should be placed alternately so that positive post of one cell is adjacent to negative post of the next cell. Positive post has "V" shape shoulder and the negative post has a square shoulder.

3. Grease all posts, straps and nuts with vaseline.

4. Connect positive posts of each cell to negative post of adjacent cell, using top connectors furnished. Top connectors are made so as to fit when connection is made between positive post of one cell and negative post of next cell. Use long connector between end cells of upper and lower shelves.

5. With all connections between cells in position, join the remaining positive post with a connection marked "Positive" leading from the electric generator. Do likewise with the remaining negative post.

6. If liquid level in any cell is 1 inch or more below the "Liquid Line" on side of glass jar, some liquid has been spilled and must be replaced. This should be done by an experienced person.

7. Immediately after installation operate electric generator and charge battery until gas bubbles rise freely through the liquid in all cells. A reading with the hydrometer syringe which is furnished with the battery should be taken, When the hydrometer float reads between 1.240 and 1.250, the battery is fully charged.

8. The time required to complete the charging operation mentioned above may vary from one to several hours, depending upon the length of time the battery has been in transit. During the charge the temperature of the cells should not be permitted to rise above 110 deg. Fahrenheit. If this condition occurs discontinue the charge or decrease the charge rate until cells have cooled off.

9. When charge is complete replace vent plugs.

The Relation Between Various Sizes of Westinghouse Farm Light Batteries and Work to be Done

The size of the battery furnished with complete farm lighting units vary greatly. Sometimes the battery size is varied with the size of the engine and generator, while again the same size of battery may be used for several sizes of engines and generators. In making replacements, while it is always necessary to retain the same number of cells, it is not necessary to retain the same size of cells.

Usually increasing the cell size increases the convenience to the owner and prolongs the life of the battery to an amount which warrants the higher cost.

With a larger battery, danger of injury through overcharging is lessened, the load on the battery is more easily carried and the engine and generator operate less frequently.

In order to give an idea of various battery capacities, below is a table showing the number of 32 volt, 25-watt lamps which may be lighted for various lengths of time from sixteen cells. The number of hours shows the length of time that the lamps will operate.

Table A

Type 3 Hours 5 Hours 8 Hours ---- ------- ------- ------- G-7 22 Lamps 14 Lamps 10 Lamps G-9 28 Lamps 19 Lamps 13 Lamps G-11 32 Lamps 24 Lamps 15 Lamps G-13 41 Lamps 29 Lamps 19 Lamps G-15 47 Lamps 33 Lamps 22 Lamps G-17 54 Lamps 38 Lamps 25 Lamps

Note:--Based on 32-Volt 25-Watt Lamps.

For example--The table shows opposite G-7 that, with the battery fully charged, twenty-two lamps may be lighted for three hours, fourteen lamps for five hours and ten lamps for eight hours, by a sixteen cell G-7 battery, without operating the engine and generator.

Motors for operating various household and farm appliances are usually rated either in horsepower or watts. The following table will give a comparison between horse-power and watts as well as the number of 25-watt lamps to which these different sizes of motors and appliances correspond.

Table B

H.P. of Motor No. of Watts Corresponding No. of 25-Watt Lamps ------------- ------------ -------------------- 1/8 93 4 1/4 185 7 1/2 373 15 3/4 559 22 1 H.P. 746 30

From table B it will be seen, for example, that a one horsepower motor draws from the battery 373 watts or the same power as do fifteen 25-watt lamps. Then referring to table A, it will be found that a G-11 battery could operate 15 lamps or this motor alone for 8 hours.

Due to the fact that a motor or electric appliance may become overloaded and therefore actually use many more watts than the name plate indicates, it is not advisable to operate any motor of over 1/4 H. P. or even an appliance of over 186 watts on the G-13 or smaller sizes unless the engine and generator are running.

It is safe, however, to operate motors or other appliances up to 375 watts on the G-15 or G-17 batteries without operating the engine and generator.

WILLARD FARM LIGHTING BATTERIES

[Fig. 328 Willard Farm Lighting Cell]

The Willard Storage Battery Co. manufactures farm lighting batteries which use sealed glass jars, or sealed rubber jars. Those using the sealed glass jars include types PH and PA. The sealed rubber jar batteries include types EM, EEW, IPR, SMW, and SEW. Both types of batteries are shipped fully charged and filled with electrolyte, and also dry, without electrolyte. The following instructions cover the installation and preparation for service of these batteries.

Glass Jar Batteries. Fully Charged and Filled With Electrolyte

Each sixteen cell set of batteries is packed in two shipping crates.

One crate, which is stenciled "No. 1" contains:

* 8 Cells. * 18 Bolt Connectors. * 1 Hydrometer Syringe. * 1 Instruction Book.

The other crate which is stenciled "No. 2" contains: 8 Cells

(NOTE:--If the batteries are re-shipped by the manufacturer or distributor, care must be exercised to see that they are sent out in sets.)

Unpacking

Remove the boards from the tops of the shipping crates and the excelsior which is above the cells.

To straighten the long top connector, grasp the strap firmly with the left hand close to the pillar post and raise the outer end of the strap until it is in an upright position. Do not make a short bend near the pillar post. Lift the cells from the case by grasping the glass jars. Do not attempt to lift them by means of the top connectors.

Clean the outside of the cells by wiping with a damp cloth.

Inspection of Cells.

Inspect each cell to see if the level of the electrolyte is at the proper height. This is indicated on the jar by a line marked LIQUID LINE.

If the electrolyte is simply a little low and there is no evidence of any having been spilled (examine packing material for discoloration) add distilled or clean rain water to bring the level to the proper height.

If the liquid does not cover the plates and the packing material is discolored, it indicates that some or all of the electrolyte has been lost from the cell either on account of a cracked jar or overturning of the battery.

If only a small quantity of electrolyte is lost through spilling, the cell should be filled to the proper height with electrolyte of the same specific gravity as in the other cells. This cell should then be charged until the gravity has ceased rising. If all the electrolyte is lost write to the Willard Storage Battery Co., Cleveland, Ohio, for instructions.

Connecting the Cells

Each cell of the type PH battery is a complete unit, sealed in a glass jar. The cells are to be placed side by side on the battery rack so that the positive terminal of one cell (long connecting strap) can be connected to the negative terminal (short strap) of the adjacent cell.

Join the positive terminal of one cell to the negative terminal of the adjacent cell and continue this procedure until all the cells are connected together. This will leave one positive and one negative terminal of the battery to be connected respectively to the positive and negative wires from the switchboard. The bend in the top connector should be made about one inch above the pillar post to eliminate the danger of breakage at the post.

In tightening the bolts do not use excessive force, as there is liability of stripping the threads.

Give the battery a freshening charge before it is put in service. Type PH cells have a gravity of 1.250 when fully charged, and 1.185 when discharged.

Willard Glass Jar Batteries Shipped "Knock-Down."

Each sixteen cell set of Batteries consists of:

16 Glass Jars. 16 Positive Groups. 16 Negative Groups. 16 Covers. 16 Vent Plugs. 32 Lead Collars. 32 Lead Keys. 32 Soft Rubber Washers. 32 Hard Rubber Rods. 64 Hard Rubber Nuts. 18 Bolt Connectors. Wood Insulators (the quantity depends upon the size of the cells). Sealing Compound. Hydrometer. Instruction Books.

Electrolyte is not supplied with batteries shipped in a knockdown condition.

Examine all packing material carefully and check the parts with the above list.

Cleaning the Glass Jars

Wash the glass jars and wipe them dry.

Preparing the Covers

Wash the covers and scrub around the under edge to remove all dust. After they are thoroughly dry place them upside down on a bench.

Melt the sealing compound and pour it around the outer edge to make a fillet in the groove.

Assembling the Element and Separators

Place the plates of a positive group between the plates of a negative group and lay the element thus formed on its edge, as shown in Fig. 329.

[Fig. 329 Inserting Separators, Willard farm lighting cell]

[Fig. 330 and Fig. 331 Fastening cover to posts, Willard farm lighting cell]

Next insert a wood separator between each of the positive and negative plates.

Next insert the hard rubber rods through the holes in the lugs of the end negative plates, and screw on the nuts. Do not screw the nuts so tight as to make the plates bulge out at the center. The rod should project the same amount on each side of the element.

Place the element in a vertical position.

The cover can now be placed over the posts. Slip a rubber washer and a lead collar over each post. The two key holes in the lead collar are unequal in size. The collar must be placed over the post so that the end which measures 3/16 inch from the bottom of the holes to the end of the collar will be next to the rubber washer. Dip the lead key in water and then put it through the holes, having the straight edge of the key on the bottom side. This operation can easily be done by using a pair of tongs (see Figs. 330 and 331) to compress the washer. After the keys are driven tight they can be cut off with a pair of end cutters and then smoothed with a file.

Sealing Element Assembly in Jar

[Fig. 332 Sealing Element Assembly, Willard farm lighting cell]

Turn the element upside down and place over a block of wood so that the weight is supported by the cover. (See Fig. 332.)

Heat the sealing compound by means of a flame (a blow torch will answer the purpose), and place the jar over the element, as shown in Fig. 331. The jar should be firmly pressed down into the compound. With a hot putty knife, clean off any compound which has oozed out of the joint. The assembled cell can now be turned to an upright position.

In case it is necessary to remove a cover, heat a wide putty knife and run it around the edge between the cover and the glass jar. This will soften the compound so that the cover can be pried off.

If it is necessary to remove the cover from the posts, the keys must be driven out by pounding on the small end, as the keys are tapered-and the holes in the lead collars are unequal in size.

Filling with Electrolyte

Fill the cells with 1.260 specific gravity electrolyte at 70° F. to the LIQUID LINE marked on the glass jars. (About I inch above the top edge of separators.) Allow the cells to stand 12 hours, and if the level of the electrolyte has lowered, add sufficient electrolyte to bring it to the proper height.

Initial Charge

Connect the positive terminal (long strap) of one cell to the negative terminal (short strap) of the adjacent cell and continue this procedure until all the cells are connected together. This will leave one positive and one negative terminal to be connected respectively to the positive and negative wires from the charging source.

The bends in the top terminal connectors should be made about one inch above the pillar posts to eliminate the danger of breakage at the post.

In tightening the bolts, do not use excessive force, as there is liability of stripping the threads.

After the cells have stood for 12 hours with electrolyte in the jars, they should be put on charge at the following rates:

Type Amperes ---- ------- PH-7 4 PH-9 5 PH-11 6-1/4 PH-13 7-1/2 PH-15 9 PH-17 10

They should be left on charge continuously until the specific gravity of the electrolyte reaches a maximum and remains constant for six hours. At this point, each cell should be gassing freely and the voltage should read about 2.45 volts per cell, with the above current flowing.

Under normal conditions it will require approximately 80 hours to complete the initial charge. The final gravity will be approximately 1.250. If the gravity is above this value, remove a little electrolyte and add the same amount of distilled water.

If the gravity is too low, remove a little of the electrolyte and add the same amount of 1.400 specific gravity acid and leave on charge as before.

After either water or acid has been added, charge the cells three hours longer in order to thoroughly mix the solution, and if at the end of that time the gravity is between 1.245 and 1.255, the cells are ready for service.

It is very important that the initial charge be continued until the specific gravity reaches a maximum value, regardless of the length of time required. The battery must not be discharged until the initial charge has been completed.

If it is impossible to charge the battery continuously, the charge can be stopped over night, but must be resumed the next day.

It is preferable to charge the battery at the ampere rate given above, but if this cannot be done, the temperature must be carefully watched so that it does not exceed 110° F.

Wilard Rubber Jar Batteries Shipped Completely Charged and Filled with Electrolyte

Immediately upon receipt of battery, remove the soft rubber nipples and unscrew the vent plugs.

The soft rubber nipples are to be discarded, as they are used only for protection during shipment. Inspect each cell to see whether the electrolyte is at the proper height.

If the electrolyte is simply a little low and there is no evidence of any having been spilled (examine packing material for discoloration), add distilled water to bring the level to the proper height.

If electrolyte does not cover the plates and the packing material is discolored, it indicates that some or all of the electrolyte has been lost from the cell, either on account of cracked jar or overturning of the battery.

If only a small quantity of electrolyte is lost through spilling, the cell should be filled to the proper height with electrolyte of the same specific gravity as in the other cells. This cell should then be charged until the gravity has ceased rising, If all the electrolyte is lost, write to the Willard Storage Battery Co., Cleveland, Ohio, for instructions.

Place batteries on rack and connect the positive terminal of one crate to the negative terminal of the next crate, using the jumpers furnished.

The main battery wires from the switch board should be soldered to the pigtail terminals, which can then be bolted to the battery terminals. Be sure to have the positive and negative battery terminals connected respectively to the positive and negative generator terminals of switchboard.

Before using the battery, it should be given a freshening charge at the rate given on page 510.

The specific gravity of the rubber jar batteries is 1.285-1.300 when fully charged, and 1.160 when discharged.

Willard Rubber Jar Batteries Shipped Dry (Export Batteries)

Batteries which have been prepared for export must be given the following treatment:

Upon receipt of battery by customer, the special soft rubber nipples, used on the batteries for shipping purposes only, should be removed and discarded.

Types SMW and SEW batteries should at once be filled to bottom of vent hole with 1.285 specific gravity electrolyte at 70° F.

In mixing electrolyte, the acid should be poured into the water and allowed to cool below 90° F. before being put into the cells. If electrolyte is shipped with the battery, it is of the proper gravity to put into the cells.

Immediately after the batteries are filled with electrolyte, they must be placed on charge at one half the normal charging rate given on page 510, and should be left on charge continuously until the specific gravity of the electrolyte stops rising. At this point, each cell should be gassing freely and the voltage should read at least 2.40 volts per cell with one-half the normal charging current flowing.

If during the charge the temperature of the electrolyte in any one cell exceeds 105° F., the current must be reduced until the temperature is below 90° F. This will necessitate a longer time to complete the charge, but must be strictly adhered to.

Under normal conditions it will require approximately 80 hours to complete the initial charge. The final gravity of the types SMW and SEW will be approximately 1.285. If the gravity is above this value, remove a little electrolyte and add same amount of distilled water while the battery is left charging (in order to thoroughly mix the solution), and after three hours, if the electrolyte is within the limits, the cell is ready for service. If the specific gravity is below these values, remove a little electrolyte and add same amount of 1.400 specific gravity electrolyte. Leave on charge as before. The acid should be poured into the water and allowed to cool below 90° P. before being used. The batteries are then ready for service.

Installing Counter Electromotive Force Cells

Counter EMF cells, if used with a battery, are installed in the same manner as regular cells. They are connected positive to negative, the same as regular cells, but the negative terminal of the CEMF group is to be connected to the negative terminal of the regular cell group. The positive terminal of the counter CEMF group is then to be connected to the switchboard.

[Image: Table of charge and discharge rates for different types of batteries, Willard farm lighting batteries]

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Definitions and Descriptions of Terms and Parts -------------------------------

Acid. As used in this book refers to sulphuric acid (H2SO4), the

## active component of the electrolyte, or a mixture of sulphuric acid

and water.

## Active Material. The active portion of the battery plates; peroxide of

lead on the positives and spongy metallic lead on the negatives.

Alloy. As used in battery practice, a homogeneous combination of lead and antimony.

Alternating Current. Electric current which does not flow in one direction only, like direct current, but rapidly reverses its direction or "alternates" in polarity so that it will not charge a battery.

Ampere. The unit of measure of the rate of flow of electric current.

Ampere Hour. The product resulting from multiplication of amperes flowing by time of flow in hours, e.g., a battery supplying 10 amperes for 8 hours gives 80 ampere hours. See note under "Volt?" for more complete explanation of current flow.

Battery. Two or more electrical cells, electrically connected so that combination furnishes current as a unit.

Battery Terminals. Devices attached to the positive post of one end cell and the negative of the other, by means of which the battery is connected to the car circuit.

Bridge (or Rib). Wedge-shaped vertical projection from bottom of rubber jar on which plates rest and by which they are supported.

Buckling. Warping or bending of the battery plates.

Burning. A term used to describe the operation of joining two pieces of lead by melting them at practically the same instant so they may run together as one continuous piece. Usually done with mixture of oxygen and hydrogen or acetylene gases, hydrogen and compressed air, or oxygen and illuminating gas.

Burning Strip. A convenient form of lead, in strips, for filling up the joint in making burned connections.

Cadmium. A metal used in about the shape of a pencil for obtaining voltage of positive or negative plates. It is dipped in the electrolyte but not allowed to come in contact with plates.

Capacity. The number of ampere hours a battery can supply at a given rate of current flow after being fully charged, e.g., a battery may be capable of supplying 10 amperes of current for 8 hours before it is exhausted. Its capacity is 80 ampere hours at the 8 hours rate of current flow. It is necessary to state the rate of flow, since same battery if discharged at 20 amperes would not last for 4 hours but for a shorter period, say 3 hours. Hence, its capacity at the 3 hour rate would be 3x2O=60 ampere hours.

Case. The containing box which holds the battery cells.

Cell. The battery unit, consisting of an element complete with electrolyte, in its jar with cover.

Charge. Passing direct current through a battery in the direction opposite to that of discharge, in order to put back the energy used on discharge.

Charge Rate. The proper rate of current to use in charging a battery from an outside source. It is expressed in amperes and varies for different sized cells.

Corrosion. The attack of metal parts by acid from the electrolyte; it is the result of lack of cleanliness.

Cover. The rubber cover which closes each individual cell; it is flanged for sealing compound to insure an effective seal.

Cycle. One charge and discharge.

Density. Specific gravity.

Developing. The first cycle or cycles of a new or rebuilt battery to bring about proper electrochemical conditions to give rated capacity.

Diffusion. Pertaining to movement of acid within the pores of plates. (See Equalization.)

Discharge. The flow of current from a battery through a circuit, opposite of "charge."

Dry. Term frequently applied to cell containing insufficient electrolyte. Also applied to certain conditions of shipment of batteries.

Electrolyte. The conducting fluid of electro-chemical devices; for lead-acid storage batteries it consists of about two parts of water to one of chemically pure sulphuric acid, by weight.

Element. Positive group, negative group and separators.

Equalization. The result of circulation and diffusion within the cell which accompanies charge and discharge. Difference in capacity at various rates is caused by the time required for this feature.

Equalizing. Term used to describe the making uniform of varying specific gravities in different cells of the same battery, by adding or removing water or electrolyte.

Evaporation. Loss of water from electrolyte from heat or charging.

Filling Plug. The plug which fits in and closes the orifice of the filling tube in the cell cover.

Finishing Rate. The current in amperes at which a battery may be charged for twenty-four hours or more. Also the charging rate used near the end of a charge when cells begin to gas.

Flooding. Overflowing through the filling tube.

Forming. Electro-chemical process of making pasted grid or other plate, types into storage battery plates. (Often confused with Developing.)

Foreign Material. Objectionable substances.

Freshening Charge. A charge given to a battery which has been standing idle, to keep it fully charged.

Gassing. The giving off of oxygen gas at positive plates and hydrogen at negatives, which begins when charge is something more than half completed-depending on the rate.

Generator System. An equipment including a generator for automatically recharging the battery, in contradistinction to a straight storage system where the battery has to be removed to be recharged.

Gravity. A contraction of the term "specific gravity," which means the density compared to water as a standard.

Grid. The metal framework of a plate, supporting the active material and provided with a lug for conducting the current and for attachment to the strap.

Group. A set of plates, either positive or negative, joined to a strap. Groups do not include separators.

Hold-Down. Device for keeping separators from floating or working up.

Hold-Down Clips. Brackets for the attachment of bolts for holding the battery securely in position on the car.

Hydrogen Flame. A very hot and clean flame of hydrogen gas and oxygen, acetylene, or compressed air used for making burned connections.

Hydrogen Generator. An apparatus for generating hydrogen gas for lead burning.

Hydrometer. An instrument for measuring the specific gravity of the electrolyte.

Hydrometer Syringe. A glass barrel enclosing a hydrometer and provided with a rubber bulb for drawing up electrolyte.

Jar. The hard rubber container holding the element and electrolyte.

Lead Burning. Making a joint by melting together the metal of the parts to be joined.

Lug. The extension from the top frame of each plate, connecting the plate to the strap.

Maximum Gravity. The highest specific gravity which the electrolyte will reach by continued charging, indicating that no acid remains in the plates.

Mud. (See Sediment.)

Negative. The terminal of a source of electrical energy as a cell, battery or generator through which current returns to complete circuit. Generally marked "Neg." or "-".

Ohm. The unit of electrical resistance. The smaller the wire conductor the greater is the resistance. Six hundred and sixty-five feet of No. 14 wire (size used in house lighting circuit) offers I ohm resistance to current flow.

Oil of Vitriol. Commercial name for concentrated sulphuric acid (1.835 specific gravity). This is never used in a battery and would quickly ruin it.

Over-Discharge. The carrying of discharge beyond proper cell voltage; shortens life if carried far enough and done frequently.

Paste. The mixture of lead oxide or spongy lead and other substances which is put into grids.

Plate. The combination of grid and paste properly "formed." Positive$ are reddish brown and negatives slate gray.

Polarity. An electrical condition. The positive terminal (or pole) of a cell or battery or electrical circuit is said to have positive polarity; the negative, negative polarity.

Positive. The terminal of a source of electrical energy as a cell, battery or generator from which the current flows. Generally marked "Pos." or "+".

Post. The portion of the strap extending through the cell cover, by means of which connection is made to the adjoining cell or to the car circuit.

Potential Difference. Abbreviated P. D. Found on test curves. Synonymous with voltage.

Rate. Number of amperes for charge or discharge. Also used to express time for either.

Rectifier. Apparatus for converting alternating current into direct current.

Resistance. Material (usually lamps or wire) of low conductivity inserted in a circuit to retard the flow of current. By varying the resistance, the amount of current can be regulated. Also the property of an electrical circuit whereby the flow of current is impeded. Resistance is measured in ohms. Analogous to the impediment offered by wall of a pipe to flow of water therein.

Rheostat. An electrical appliance used to raise or lower the resistance of a circuit and correspondingly to decrease or increase the current flowing.

Rib. (See Bridge.)

Ribbed. (See Separator.)

Reversal. Reversal of polarity of cell or battery, due to excessive discharge, or charging in the wrong direction.

Rubber Sheets. Thin, perforated hard rubber sheets used in combination with the wood separators in some types of batteries. They are placed between the grooved side of the wood separators and the positive plate.

Sealing. Making tight joints between jar and cover; usually with a black, thick, acid-proof compound.

Sediment. Loosened or worn out particles of active material fallen to the bottom of cells; frequently called "mud."

Sediment Space. That part of jar between bottom and top of bridge.

Separator. An insulator between plates of opposite polarity; usually of wood, rubber or combination of both. Separators are generally corrugated or ribbed to insure proper distance between plates and to avoid too great displacement of electrolyte.

Short Circuit. A metallic connection between the positive and negative plates within a cell. The plates may be in actual contact or material may lodge and bridge across. If the separators are in good condition, a short circuit is unlikely to occur.

Spacers. Wood strips used in some types to separate the cells in the case, and divided to provide a space for the tie bolts.

Specific Gravity. The density of the electrolyte compared to water as a standard. It indicates the strength and is measured by the hydrometer.

Spray. Fine particles of electrolyte carried up from the surface by gas bubbles. (See Gassing.)

Starting Rate. A specified current in amperes at which a discharged battery may be charged at the beginning of a charge. The starting rate is reduced to the finishing rate when the cells begin to gas. It is also reduced at any time during the charge if the temperature of the electrolyte rises to or above 110 deg. Fahrenheit.

Starvation. The result of giving insufficient charge in relation to the amount of discharge, resulting in poor service and injury to the battery.

Strap. The leaden casting to which the plates of a group are joined.

Sulphate. Common term for lead sulphate. (PbSO4.)

Sulphated. Term used to describe cells in an under-charged condition, from either over-discharging without corresponding long charges or from standing idle some time and being self discharged.

Sulphate Reading. A peculiarity of cell voltage when plates are considerably sulphated, where charging voltage shows abnormally high figures before dropping gradually to normal charging voltage.

Terminal. Part to which outside wires are connected.

Vent, Vent Plug or Vent-Cap. Hard or soft rubber part inserted in cover to retain atmospheric pressure within the cell, while preventing loss of electrolyte from spray. It allows gases formed in the cell to escape, prevents electrolyte from spilling, and keeps dirt out of the cell.

Volt. The commercial unit of pressure in an electric circuit. Voltage is measured by a voltmeter. Analogous to pressure or head of water flow through pipes. NOTE.--Just as increase of pressure causes more volume of water to flow through a given pipe so increase of voltage (by putting more cells in circuit) will cause more amperes of current to flow in same circuit. Decreasing size of pipes is increasing resistance and decreases flow of water, so also introduction of resistance in an electrical circuit decreases current flow with a given voltage or pressure.

Wall. Jar sides and ends.

Washing. Removal of sediment from cells after taking out elements; usually accompanied by rinsing of groups, replacement of wood separators and renewal of electrolyte.

Watt. The commercial unit of electrical power, and is the product of voltage of circuit by amperes flowing. One ampere flowing under pressure of one volt represents one watt of power.

Watt Hour. The unit of electrical work. It is the product of power expended by time of expenditure, e.g., 10 amperes flowing under 32 volts pressure for 8 hours gives 2560 watt hours.

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Index

A

Acetic acid from improperly treated separators 77 Acetylene and Compressed Air Lead-burning Outfit147 Acid Carboys 184 Acid. Handling and mixing 222 Acid. How lost while battery is on car 57 Acid. How to draw, from carboys 184 Acid should never be added to battery on car 57 Acid used instead of water 57

## Active materials. Composition of 13

## Active materials. Effect of quantity, porosity, and arrangement of, on

capacity 42

## Active materials. Resistance of 49

Age codes 242 Age of battery. Determining 242 Age of battery. Effect of, on capacity 47 Alcohol torch lead-burning outfit 148 Applying pastes to grids 11 Arc lead-burning outfit 148 Audion bulb for radio receiving sets 253

B

Battery box should be kept clean and dry 51 Battery carrier 173 Battery case (see Case). Battery steamer 158 Battery truck 173 Battery turntable 170 Bench charge 198 to 210 Bench charge. Arrangement of batteries for 200 Bench charge. Charging rates for 201 Bench charge. Conditions preventing batteries from charging 206 Bench charge. Conditions preventing gravity from rising 207 Bench charge. If battery becomes too hot 205 Bench charge. If battery will not hold a charge 208 Bench charge. If battery will not take half a charge 205 Bench charge. If current cannot be passed through battery 206 Bench charge. If electrolyte has a milky appearance 206 Bench charge. If gravity rises above 1.300 205 Bench charge. If gravity rises long before voltage does 205 Bench charge. If new battery will not charge 205 Bench charge. If one cell will not charge 205 Bench charge. If vinegar-like odor is detected 205 Bench charge. Leave vent-plugs in when charging 209 Bench charge. Level of electrolyte at end of 203 Bench charge. Painting case after 203 Bench charge. Specific gravity at end of 203 Bench charge. Specific gravity will not rise to 1.280 204 Bench charge. Suggestions for 209 Bench charge. Temperatures of batteries during 202 Bench charge. Time required for 203 Bench charge. Troubles arising during 204 Bench charge. Voltage at end of 203 Bench charge. When necessary 198 Bins for stock parts 158 Book-keeping records 302 (Omitted) "Bone-dry" batteries. Putting into service 229 Boxes for battery parts 183 Buckling 72 Buckling. Caused by charging at high rates 73 Buckling. Caused by continued operation in discharged condition 73 Buckling. Caused by defective grid alloy 73 Buckling. Caused by non-uniform current distribution 73 Buckling. Caused by overdischarge 73 Buckling does not necessarily cause trouble 73 Burning. (See Lead-Burning.) Burning-lead mould 164 Burning rack 162 Business methods 299 to 312 (Omitted)

C

Cadmium. What it is 176 Cadmium leads. Connection of, to voltmeter 179 Cadmium readings affected by improperly treated separators 181 Cadmium readings. Conditions necessary to obtain good negative-cadmium readings 210 Cadmium readings do not indicate capacity of a cell 175 Cadmium readings on short-circuited cells 180 Cadmium readings. Troubles shown by, on charge 206 Cadmium readings. When they should be taken 176 Cadmium test 174 Cadmium test. How made 175 Cadmium test on charging battery 181 Cadmium test on discharging battery 180 Cadmium test set. What it consists of 177 Cadmium test voltmeter 178 Calling for repair batteries 314 Capacity. Effect of age of battery on 47 and 89 Capacity. Effect of plate surface area on 42 Capacity. Effect of clogged separators on 88 Capacity. Effect of incorrect proportions of acid and acid in electrolyte on 88 Capacity. Effect of low level of electrolyte on 88 Capacity. Effect of operating conditions on 44 Capacity. Effect of quantity and strength of electrolyte on 42 Capacity. Effect of quantity, arrangement, and porosity of active materials on 42 Capacity. Effect of rate of discharge on 44 Capacity. Effect of reversal of plates on 89 Capacity. Effect of shedding on 88 Capacity. Effect of specific gravity on 43 Capacity. Effect of temperature on 46 Carbon-arc lead-burning outfit 148 Carboys 184 Care of battery on the car 51 to 68 Care of battery when not in service 67 Carrier for batteries 173 Case. Cleaning and painting, after repairs 372 Case manufacture 22 Case. Painting, after bench charge 203 Case. Repairing 360 Case. Troubles indicated by rotted 319 Case troubles 83 Cases. Equipment for work on 98 and 170 Casting plate grids 9 Cell connector mould 168 Cell connectors. Burning-on 213 Cell connectors. Equipment for work on 98 Cell connectors. How to remove 329 Changing pastes into active materials 12 Charge. (See Bench Charge.) Charge. Changes at negative plates during 30 and 39 Charge. Changes at positive plates during 30 and 40 Charge. Changes in acid density during 39 Charge. Changes in voltage during 38 Charge. Loss of, in an idle battery 89 Charge. Preliminary, in rebuilding batteries 349 Charge. Trickle 239 Charging bench133 to 139 Charging bench. Arrangement of batteries on 200 Charging bench. Temperature of batteries on 202 Charging bench. Working drawings of 134 to 139 Charging circuits. Drawings of 105 Charging connections. Making temporary 220 Charging. Constant potential 111 Charging equipment for farm lighting batteries 439 Charging equipment for starting batteries 100 Charging farm lighting batteries 455 Charging. Lamp-banks for 101 Charging. Motor-generators for 106 Charging rate. Adjusting 287 Charging rate. Checking 283 Charging rate. Governed by gassing 112 and 202 Charging rate. How and when to adjust 289 Charging rates for bench charge 112 and 201 Charging rates for new Exide batteries 226 Charging rates for new Philadelphia batteries 228 Charging rates for new Prest-O-Lite batteries 234 Charging rates on the car 283 Charging rebuilt batteries 373 Charging. Rheostats for 101 Chemical actions and electricity. Relations between 31 Chemical changes at the negatives during charge 30 Chemical changes at the positives during charge 30 Chemical changes at the negatives during discharge 29 Chemical changes at the positives during discharge 29 Chemical changes in the battery 27 to 31 Composition of jars 16 Composition of plate grids 9 Compound. Scraping, from covers and jars 334 Compressed air and hydrogen lead-burning outfit 147 Compressed air and illuminating gas lead-burning outfit 149 Condenser for making distilled water 160 Connections. Making temporary, for charging 220 Connectors. (See Cell Connectors.) Connector troubles 84 Constant-potential charging 111 Construction of plate grids 10 Convenient method of adding water 56 Corroded grids 77 Corroded grids. Caused by age 78 Corroded grids. Caused by high temperatures 78 Corroded grids. Caused by impurities 78 Corrosion 321 Covers. Eveready 17 Covers. Exide 19 and 21 Covers. Functions of 16 Covers. Gould 17 Covers. How to remove 331 Covers. Philadelphia diamond grid 16 Covers. Prest-O-Lite 18 and 19 Covers. Putting on the 365 Covers. Sealing 366 Covers. Single and double 16 Covers. Steaming 332 Covers. U.S.L. 18 and 20 Covers. Vesta 18 Covers. Westinghouse 417 Covers. Willard 19 Credit. Use and abuse of 301 (Omitted) Cutout. Checking action of 282? Cycling discharge tests 269

D

Dead cells. Causes of 87 Delco-Light batteries 466 Delco-Light batteries. Ampere-hour meter for 467 and 471 Delco-Light batteries. Burning-on new plates of 492 Delco-Light batteries. Burning-on new straps for 488 Delco-Light batteries. Care of cells of, in stock 493 Delco-Light batteries. Charging, after reassembling 481 Delco-Light batteries. Charging outside negatives of 484 Delco-Light batteries. Clearing high resistance shorts in 484 Delco-Light batteries. Clearing lug shorts in 484 Delco-Light batteries. Dis-assembling 474 Delco-Light batteries. Gauges and instruments for testing 466 Delco-Light batteries. General complaints from users of 495 Delco-Light batteries. Hydrometers for 468 Delco-Light batteries. Inspection trips 470 Delco-Light batteries. Pressing negatives of 485 Delco-Light batteries. Putting repaired cells into service 484 Delco-Light batteries. Re-assembling 477 Delco-Light batteries. Removing impurities from 483 Delco-Light batteries. Repairing broken posts of 487 Delco-Light batteries. Repairing lead parts of 486 Delco-Light batteries. Salvaging replaced cells of 486 Delco-Light batteries. Taking, out of commission 494 Delco-Light batteries. Treating broken cells of 482 Delco-Light batteries. Treating spilled cells of 482 Delco-Light batteries. Treating reversed cells of 483 Delco-Light batteries. Use of auxiliary straps with 492 Delco-Light batteries. When and how to charge 468 Discharge apparatus 270 Discharge. Changes at negative plates during 37 Discharge. Changes at positive plates during 37 Discharge. Changes in acid density during 35 Discharge. Chemical actions at negative plates during 29 Discharge. Chemical actions at positive plates during 29 Discharge. Effects of rates of, on capacity 44 Discharge. Voltage changes during 32 Discharge tests. Cycling 269 Discharge tests. Fifteen seconds 266 Discharge tests. Lighting ability 267 Discharge tests. Starting ability 267 Distilled water. Condenser for making 160 Dope electrolytes 59 and 199 Double covers. Sealing 366 Dry shipment of batteries 24 Dry storage 240 Dry storage batteries 265

E

Earthenware jars 184 Electrical system. Normal course of operation of 277 Electrical system. Testing the 276 Electrical system. Tests on, to be made by the repairman 279 Electrical system. Troubles in the 284 Electricity and chemical actions. Relation between 31 Electrolyte. Adjusting the 373 Electrolyte below tops of plates. Causes and results of 319 and 323 Electrolyte. Causes of milky appearance of 206 Electrolyte. Composition of 199 and 222 Electrolyte. Correct height of, above plates 55 Electrolyte. Effect of circulation of, on capacity 44 Electrolyte. Effect of low 67 Electrolyte. Effect of quantity and strength of, on capacity 42 Electrolyte. Freezing points of 67 Electrolyte. Leaking of, at top of cells 324 Electrolyte. Level of, at end of bench charge 203 Electrolyte. Resistance of 43 and 48 Electrolyte troubles. High gravity 85 Electrolyte troubles. High level 85 Electrolyte troubles. Low gravity 85 Electrolyte troubles. Low level 85 Electrolyte troubles. Milky appearance 85 Element. Tightening loose 363 Elements. Re-assembling 361 Equipment for discharge tests 270 Equipment for general work 98 Equipment for general work on connectors and terminals 98 Equipment for handling sealing compound 149 Equipment for lead-burning 97 Equipment for work on cases 98 and 170 Equipment needed in opening batteries 97 Equipment which is absolutely necessary 96 Eveready batteries. Claimed to be non-sulphating 401 Eveready batteries. Description of parts 404 Eveready batteries. Rebuilding 405 Examining and testing incoming batteries 317 Exide farm lighting batteries 466 to 498 Exide radio batteries 257 Exide starting batteries. Age code for 243 (Age code chart omitted) Exide starting batteries. Burning-on cell connectors of 382 Exide starting batteries. Capacities of 381 (Chart omitted) Exide starting batteries. Charging, after repairing 382 Exide starting batteries. Methods of holding jars of, in case 377 Exide starting batteries. Opening of 377 Exide starting batteries. Putting cells of, in case 382 Exide starting batteries. Putting jars of, in case 382 Exide starting batteries. Putting new, into service 225 Exide starting batteries. Re-assembling plates of 379 Exide starting batteries. Sealing single covers of 380 Exide starting batteries. Type numbers of 377 Exide starting batteries. Types of 375 Exide starting batteries. Work on plates, separators, jars, and cases of 379

F

Farm lighting batteries 435 to 510 Farm lighting batteries. Care of, in operation 453 Farm lighting batteries. Care of plant of, in operation 450 Farm lighting batteries. Charging 453? or (455) Farm lighting batteries. Charging equipment for 439 Farm lighting batteries. Determining condition of cells of 453 Farm lighting batteries. Difference between, and starting batteries 435 Farm lighting batteries. Discharge rules for 457 Farm lighting batteries. Exide 466 Farm lighting batteries. Initial charge of 448 Farm lighting batteries. Installation of plant 445 Farm lighting batteries. Instructing users of 449 Farm lighting batteries. Jars used in 436 Farm lighting batteries. Loads carried by 443 (Charts omitted) Farm lighting batteries. Location of plant 444 Farm lighting batteries. Overcharge of 455 Farm lighting batteries. Power consumed by appliances connected to 442 Farm lighting batteries. Prest-O-Lite 460 Farm lighting batteries. Selection of plant 440 Farm lighting batteries. Separators for 438 Farm lighting batteries. Size of plant required 442 Farm lighting batteries. Specific gravity of electrolyte of 438 Farm lighting batteries. Troubles with 458 Farm lighting batteries. When to charge 455 Farm lighting batteries. Wiring of plant for 444 Filling and testing service 291 Flames for lead-burning 211 Floor. Care of 188 Floor grating for shop 188 Floor of shop 186 Forming plates 11 Freezing points of electrolyte 67

G

Gassing causes shedding 74 Gassing. Charging rate governed by 112 and 202 Gassing. Definition of 31 Gassing. Excessive, causes milky appearance of electrolyte 86 Gassing of sulphated plates 40 and 75 Gassing on charge 37? and 202 Granulated negatives 78 Granulated negatives. Caused by age 78 Granulated negatives. Caused by heat 78 Gravity. (See Specific Gravity). Grids. Casting 9 Grids. Composition of 9 Grids. Corroded 77 Grids. Effect of age on 78 and 80 and 342? (344) Grids. Effect of defective grid alloy on 73 Grids. Effect of impurities on 77 and 78 and 80 and 342 Grids. Effect of overheating on 78 and 80 and 342? Grids. Resistance of 48 Grids. Trimming 10

H

Handling and mixing acid 222 Heating of negatives exposed to the air 78 High rate discharge testers 181 High rate discharge tests 266 and 267 and 374 Home-made batteries 25 Hydrogen and compressed air lead-burning outfit 147 Hydrogen and oxygen lead-burning outfit 146 Hydrometer. What it consists of 60 Hydrometer readings. Effect of temperature on 65 Hydrometer readings. How to take 61

I

Idle battery. Care of 67 Idle battery. How it becomes discharged 89 Idle battery. How it sulphates 70 Illuminating gas and compressed air lead-burning outfit 149 Impurities 76 Impurities which attack the plates 77 Impurities which cause self-discharge 76 Incoming batteries. Examining and testing 317 Incoming batteries. General inspection of 320 Incoming batteries. Operation tests on 320 Incoming batteries. When it is necessary to open 326 Incoming batteries. When it is necessary to remove from car 325 Incoming batteries. When it is unnecessary to open 325 Incoming batteries. When it is unnecessary to remove from car 324 Installing battery on the car 236 Internal resistance 48 to 50 Isolators 408 Inspection to determine height of electrolyte 55

J

Jars. Construction of 16 Jars. Filling with electrolyte 364 Jars for farm lighting batteries 436 Jars. Manufacture of 16 Jars. Materials used for 16 Jars. Removing defective 359 Jars. Testing, for leaks 356 Jars. Work on 356 Jar troubles caused by explosion in cell 83 Jar troubles caused by freezing 83 Jar troubles caused by improperly trimmed groups 83 Jar troubles caused by loose battery 82 Jar troubles caused by rough handling 82 Jar troubles caused by weights placed on top of battery 83

K

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L

Lead burning cell connectors 213 Lead burning. Classes of 211 Lead burning. Equipment for 97 and 143 Lead burning. General instructions for 210 to 220 Lead burning plates to straps 217 Lead burning terminals 213 Lead burning. Safety precautions for 213 Lead melting pots 220 Lead mould 164 Lead moulding instructions 220 Light for shop 187 and 190 Loose active material 75 Loose active material caused by buckling 76 Loose active material caused by overdischarge 75 Loss of capacity 88 Loss of charge in an idle battery 89 Lugs. Extending plate 219

M

Manufacture of batteries 9 to 26 Manufacture of batteries. Assembling and sealing 23 Manufacture of batteries. Auxiliary rubber separators 15 Manufacture of batteries. Cases 22 Manufacture of batteries. Casting the grid 9 Manufacture of batteries. Composition of the grid 9 Manufacture of batteries. Covers 16 Manufacture of batteries. Drying the pasted plates 12 Manufacture of batteries. Forming the plates 12 Manufacture of batteries. Home-made batteries 25 Manufacture of batteries. Jars 16 Manufacture of batteries. Materials used for separators 14 Manufacture of batteries. Mixing pastes 11 Manufacture of batteries. Paste formulas 11 Manufacture of batteries. Pasting plates 11 Manufacture of batteries. Philco slotted retainer 15 Manufacture of batteries. Post seal 16 Manufacture of batteries. Preparing batteries for dry shipment 24 Manufacture of batteries. Separators 14 Manufacture of batteries. Terminal connections 25 Manufacture of batteries. Treating separators 14 Manufacture of batteries. Trimming the grid 10 Manufacture of batteries. Vent plugs 22 Manufacture of batteries. Vesta impregnated mats 15 Mechanical rectifier 131 Melting pot for lead 220 Mercury-Arc rectifier 129 Milky electrolyte 206 Motor-generators 106 to 112 Motor-generators. Care of 110 Motor-generators. Operating charging circuits of 109 Motor-generators. Sizes for small and large shops 106 Motor-generators. Suggestions on 108 Moulding instructions 220 Moulding materials 220 Moulds. 164 to 170 Moulds for building up posts 165 Moulds for burning lead sticks 164 Moulds for cell connectors 168 Moulds for plate straps 167 and 169 Moulds for terminal screws 168

N

Negative plates. Changes at, during charge 39 Negative plates. Changes at, during discharge 37 Negatives. Bulged 79 Negatives. Granulated 78 Negatives. Heating of, when exposed to the air 78 Negatives with roughened surface 79 Negatives with softened active material 79 Negatives with hard active material 79 Negatives. Washing and pressing 351 New batteries. Putting, into service 224 Non-sulphating Eveready batteries 402

O

Open-circuits 86 Open-circuits. Caused by acid on soldered joints 86 Open-circuits. Caused by broken terminals 86 Open-circuits. Caused by poor lead burning 86 Opening batteries. Equipment needed in 97 Opening batteries. Heating sealing compound 332 Opening batteries. Instructions for 328 Opening batteries. Pulling elements out of jars 333 Opening batteries. Removing connectors and terminals 329 Opening batteries. Removing post-seal 331 Opening batteries. Scraping compound from covers 334 Opening batteries. When necessary 326 Opening batteries. When unnecessary 325 Operating conditions. Effect of, on capacity 44 Overdischarge causes sulphation 69 Oxides used for plate pastes 11 Oxygen and acetylene lead burning outfit 143 Oxygen and hydrogen lead burning outfit 146 Oxygen and illuminating gas lead burning outfit 146

P

Packing batteries for shipping 271 Painting case after bench charge 203 Paraffine dip pot 182 Paste formulas 11 Pastes. Applying to grids 11 Patent electrolytes 59 Philadelphia radio batteries 260 Philadelphia starting batteries. Age codes for 243 Philadelphia starting batteries. Old type post seal for 398 Philadelphia starting batteries. Putting new, into service 228 Philadelphia starting batteries. Rubber cases for 401 Philadelphia starting batteries. Rubber-Lockt seal 399 Philadelphia starting batteries. Separators for 402 Plante plates 27 Plante's work on the storage battery 27 Plate burning-rack 162 Plate lugs. Extending 219 Plate press 171 Plate strap mould 167 and 169 Plate surface area. Effect of, on capacity 42 Plate troubles 69 Plates. Burning, to straps 217 and 355 Plates charged in wrong direction 81 and 343 Plates. Examining, after opening battery 337 Plates. Sulphated 342 Plates. When old, may be used again 344 Plates. When to put in new 339 Positives. Buckled 80 and 341 Positives. Changes at, during charge 40 Positives. Changes at, during discharge 37 Positives. Frozen 80 and 339 Positives. Rotted, and disintegrated 80 and 341 Positives. Washing 354 Positives which have lost considerable active material 80 Positives with hard active material 81 Positives with soft active material. 80 Post builders 165 Post building instructions 218 Post seal 17 Post seal. Exide 19 Post seal. Philadelphia 399 Post seal. Prest-O-Lite 386 Post seal. Titan 434 Post seal. Universal 430 Post seal. U.S.L. 18 Post seal. Vesta 413 Post seal. Westinghouse 417 Post seal. Willard 424 to 428 Posts. Burning, to plates 217 Pots for melting lead 220 Pressing plates 171 Piest-O-Lite farm lighting batteries 460 Prest-O-Lite farm lighting batteries. Descriptions 460 Prest-O-Lite farm lighting batteries. Opening cells 464 Prest-O-Lite farm lighting batteries. Putting repaired cell into service 465 Prest-O-Lite farm lighting batteries. Rebuilding 464 Prest-O-Lite farm lighting batteries. Specific gravity of electrolyte 461 Prest-O-Lite radio batteries 262 Prest-O-Lite starting batteries. Age code for 244 (Omitted) Prest-O-Lite starting batteries. Peening instructions for 395 Prest-O-Lite starting batteries. Old style covers for 386 Prest-O-Lite starting batteries. Peened post seal for 386 Prest-O-Lite starting batteries. Peening posts of 391 and 394 Prest-O-Lite starting batteries. Peening press for 390 Prest-O-Lite starting batteries. Post locking outfit for 388 Prest-O-Lite starting batteries. Putting new into service 233 Prest-O-Lite starting batteries. Rebuilding posts of 393 Prest-O-Lite starting batteries. Removing covers from 392 Prest-O-Lite starting batteries. Tables of 396 (Omitted) Primary cell 5 Purchasing methods 299 (Omitted) Putting new batteries into service 224

Q

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R

Radio audion bulb 253 Radio batteries 252 Radio batteries. Exide 257 Radio batteries. General features of 255 Radio batteries. Philadelphia 260 Radio batteries. Prest-O-Lite 262 Radio batteries. Universal 263 Radio batteries. U. S. L. 261 Radio batteries. Vesta 256 Radio batteries. Westinghouse 259 Radio batteries. Willard 257 Radio receiving sets. Types of 252 Rebuilding batteries 328 (to rest of