The Automobile Storage Battery Part 51

If you find that the separator pores are still open, leave the separators in place and proceed to separate the plates that are touching. How? That depends on what insulating material you have available that is thin enough. If nothing else is available, take a piece of new dry separator about 3/8 inch to 1/2 inch square, or a piece of pasteboard the same size. Use a screw driver or putty knife to separate the plates far enough to insert the little piece of insulation as in Fig. 216. Free all the shorts in this way, unless you have some old rubber insulators. In this case, break off some narrow strips 3/4 inch wide or less, put two together and repeat the operation as above, using the rubber strips instead of the pieces of separator. Insert down 1/2 inch or so and bend over and break off.

Occasionally the Lipper edges of the plates are shorted, in which case they must be treated the same way.

[Fig. 216 Clearing short circuits]

[Fig. 217 Cleaning scale from posts before replacing connectors temporarily for charge]

Charging

When you have in this way cleared all the "shorts" in the elements place the elements back in the jars in the same position as they were when you opened the battery, and add enough distilled water to the electrolyte to cover the plates to a depth of one-half inch.

If the negatives are badly sulphated (active material very hard), they will charge more quickly if all the old electrolyte is dumped out and the cells filled with distilled water before putting the battery on charge. This "water cure" is the best for sulphated negatives and will save many plates that could otherwise not be used again. Make it a rule to replace the old electrolyte with distilled water if negatives are sulphated.

[Fig. 218]

Fig. 218. Tapping Connectors in Place.

Preparatory to Charging After Battery Has Been Opened and Shorts Removed

The next operation is to put the battery on charge. Grasp each post in the jaws of a pair of gas pliers and work the pliers back and forth, Fig. 217, so as to remove the scale and allow the connecting straps to make good contact. Now take a knife and cut off the rough edges left in the connecting straps by the drill. Taper the edge, if necessary to go on post. Turn the connectors upside down and pound gently in position, Fig. 218, to make a good connection. Temporary charging connections may also be made by burning lead strips on the posts. This being properly done, the battery is ready for charging. Check up the connections to be sure they are correct.

Now put the battery on charge, and charge at a low rate. Do not allow the temperature of any cell to rise above 110F. Continue the charge until the electrolyte clears up, and its specific gravity stops rising and the plates have a normal color over their entire surface. Fully charged positive plates have a chocolate brown color, and fully charged negative plates have a dark gray color. By holding an electric light directly over a cell, and looking down, the color of both negatives and positives may be determined. Do not take the battery off charge until you have obtained these results, although it may be necessary to continue the charge for two, three, four, or five days.

In this preliminary charge it is not necessary to bring the gravity up to 1.280, because the electrolyte is not to be used again, and the plates will become charged completely, regardless of what the gravity is. The essential thing is to charge until the electrolyte becomes perfectly clear, the gravity stops rising, and the plates have the right color. The Cadmium test may be used here to determine when the plates are charged. If the gravity rises above 1.280 during the preliminary charge, adjust it to 1.280 by drawing out some of the electrolyte and adding distilled water. The battery must stay on charge until you have the desired conditions. If one cell does not charge,--that is, if its specific gravity does not rise,--you have probably not freed all the shorts, and must take the element out of the jar again and carefully inspect it for more shorts.

Right here is where one of the most important questions may be asked about rebuilding batteries. Why must you free the shorts and put the battery on charge? Why not save time by putting in all new separators, sealing the battery, burning on the cell connectors, and then putting it on charge? If you have ever treated a battery in this way, what results did you get? Why did you have a badly unbalanced gravity of electrolyte? How could you know what specific gravity electrolyte to put in each cell? Perhaps one was charged, one only half charged, and the other dead. Suppose the dead cell had impurities in it. How could you get rid of them? Suppose the battery showed poor capacity on test, what would you do?

Washing and Pressing the Negatives

To continue the actual work on the battery. The battery being fully charged,--the electrolyte clear, the plates of normal color, the specific gravity no longer rising,-- remove it from the charging bench and put it on the work bench. Draw each element and let drain as in Fig. 197.

[Fig. 219 Nesting plates]

Here again the labeled boxes described on page 183 come in handy.

Separate one group, remove the separators, and put one group in each end of box to keep clean. Separate another group, And nest the plates, Fig. 219, the negative with the negative, and positive with positive.

Separate the third element and put groups in the boxes. Pour the old electrolyte out of the jars, and wash out the jars as described on page 360. You now have the plates in the best possible shape for handling. Take the boxes containing the plates to the sink. Have the plate press and the plate press boards ready for use.

If, for any reason, you are called away from your work at this point to be gone for five minutes, do not leave the fully charged negatives exposed to the air, as they will become very hot. Cover them with water. A one-gallon stone or earthenware jar will hold the negative plates of a 100 ampere hour battery if you nest two of the groups. You may also put negatives back in jars from which they were taken, and fill with water.

Now hold a negative group under the faucet, and let a strong stream of water run down over each plate so as to wash it thoroughly, and to remove any foreign matter from the plate surfaces. All negative groups must be handled in exactly the same way so as to get the same results in each case.

After you have washed the first group, place it on edge on a clean board with the post down and pointing away from you, and the bottom of the group toward you. Now insert plate press boards which are slightly larger than the plates, and of the exact thickness required to fill the s.p.a.ces between plates, Fig. 113. For the standard 1/8 inch plates, a 5-16 inch board, or two 1/8 inch boards should be placed between plates.

The 1/8 inch boards are actually more than 1/8 inch thick, and will give the proper s.p.a.cing. For thin plates, use 1/4 inch boards. Do not push the plate press boards more than 1/8 inch above the tops of the plates, and be sure that the boards cover the entire plates. Put a board on the outside of each end plate of the group. In this way insert the plate press boards in each of the three negative groups.

Then place each negative group on the lower jaw of the plate press with the post of each group pointing toward you. Three groups may be pressed at one time. Bring the top edges of the transite boards flush with the front edge of the lower jaw of the press, so that no pressure will be applied to the plate lugs. See Fig. 114. Pressure applied to the plate lugs will break them off.

Now screw down the upper jaw of the press as tightly as you can with the handwheel, so as to put as much pressure on the plates as possible. Leave the plates in the press for about five minutes. Then remove them from the press, take out the boards, and replace the plates in the battery jar from which they were removed, and cover with water. They may also be placed in a stone or earthernware jar and covered with water, especially if there is any work to be done on the jars or case of the battery. If the spongy lead of the negatives is firm, they may be rea.s.sembled in the battery as soon as they have been pressed. If, however, the spongy lead is soft and mushy, keep the negatives covered with water for 12 to 24 hours. This will make them hard and firm. Then remove them from the water and dry them in the air. In drying, the plates will become heated and will steam. As soon as you notice any steaming, dip the plates in water until they are cool. Then remove them from the water and continue the drying process.

Each time the negatives begin to steam as they dry in the air, dip them in the water until they are cool.

When the negatives are dry, they are ready to be rea.s.sembled in the battery and prepared for service. Negatives treated in this way will give good service for a much longer time than they would if not treated in this way. The spongy lead has been made firm and elastic.

If you have other negatives in your shop which are not in use, treat them in the same way and put them away for future use, to use as rental batteries. Always put them through the same process:

1. Charge them fully.

2. Press them in the plate press to force the spongy lead back into the grids.

3. Soak them in water, if the spongy lead is soft and mushy, for 12 to 24 hours, or even longer until the spongy lead is firm. Dry them in the air, dipping them in water whenever they begin to steam and become heated. This will give you negatives that will give excellent service and have a long life. Many negatives treated in this way will be good for fifteen months to two years of additional service. The rental batteries should be a.s.sembled in the same way as those you are rebuilding for the owners.

The importance of pressing negatives cannot be exaggerated. Always press the negatives of the batteries which you rebuild. Do not do it to half, or three-fourths of the negatives, but to all of them. The work takes but a few minutes, and the time could not be put to better advantage. The spongy lead of the negatives swells and bulges out and makes very poor contact with the grids as a battery becomes discharged. This results in a loss of capacity, gradual sulphation of the loose active material, corrosion of the grids, failure of the gravity to rise high enough on charge, overheating of the battery on charge, ga.s.sing before the sulphate is reduced to active material with breaking off and roughening of the active material, and makes the battery lazy and sluggish in action. The spongy lead must make good contact with the grids if the battery is to have a long life and give good service.

No amount of charging will cure a negative with bulged, swollen active material. Once this material becomes bulged nothing but pressing will put it back where it belongs, and until it is pressed back into the grids the plates are in a poor condition for service. Even if the bulging is but very slight, the plates must be pressed.

Washing Positives

If you intend to use some of the positives, they should now be washed.

If you intend to use all new positives, throw away the old ones, of course. The positives should not be held under the faucet as the negatives were, because the stream of water will wash out much of the positive active material. Rinse the positives a number of times in a jar of clean water by moving them up and down in the water. This will remove impurities from the surfaces of the plates and wash off any foreign or loose materials. After rinsing each positive group, replace it in the box.

Never attempt to straighten badly buckled positives, as the bending cannot be done successfully, and the active material will not have good contact with the grids. Positives cannot be pressed as negatives can, because the positive active material lacks the elasticity and toughness of the negative spongy lead. Slightly buckled positives may sometimes be straightened by bending them lightly all around the edges with a pair of thin, wide nosed pliers. This should be done very carefully, however, and the straightening done gradually. If the plates cannot be straightened in this way and the separators do not lie perfectly flat against them without pinching at the corners, the plates should be discarded, and new ones used in their place.

This is all the work to be done on the old plates, and those which are to be used again are ready to be rea.s.sembled in the battery. The process of treating the plates should be followed in every battery that you rebuild, and the same steps should always be taken, and in the same order. With one Standard method of rebuilding batteries you will do uniformly good work and satisfy all your customers. The essential thing for the success of your battery business is to learn the Standard method and use it. Do not rush a battery through your shop, and leave out some of the steps of the process, even though the owner may be in a hurry. If you have a good stock of rental batteries you can put one on his car and keep it there until you have done as good a job of rebuilding on his battery as you possibly can. Remember that the Standard method which has been described has not simply been figured out as being a good method. This method has been worked out in the actual rebuilding of thousands and thousands of batteries of all makes and in all conditions, and has produced batteries full of life and power, ready to give one to two years more of good, reliable service.

Burning on Plates

When you put new plates into a battery, or find some of the plates broken from the connecting strap, it will be necessary to burn the plates to the strap. Frequently you will find plates which are otherwise in a good condition broken from the connecting straps. This is most likely to happen when the plates have been cast on to the connecting strap instead of being burned on. These plates must be burned on.

New plates are frequently necessary. From pages 339 to 346 you see that new plates are required under the following conditions:

(a) Positives. Ruined by freezing; weak and brittle from age, large part of active material shed; badly buckled; rotten and disintegrated by impurities; reversed. Positives in a reasonably good mechanical condition can be restored to a good electrical condition by charging.

(b) Negatives. Active material granulated, bulged and disintegrated; charged while dry; positives disintegrated by impurities; ruined by overcharging; badly sulphated because allowed to stand idle, or used while discharged; much active material lost, and that which is left soft and mushy; negatives reversed by charging battery backwards.

When making plate renewals, never install plates of different design in the same group. Always use plates of the type intended for the battery. The battery should first be fully charged, as already explained. If all the plates in a group are to be discarded, clamp the post in a vise, being careful not to crack the hard rubber sh.e.l.l if one is on it, or to damage the threads on Posts such as the Exide or to draw up the vise so tightly as to crush the post. Then saw off all the old plates with a new coa.r.s.e toothed hacksaw, a sharp key hole saw, or any good saw which has a wide set, close to the post. This separates the entire group of plates from the post in one short operation. This method is much better than the one of sawing the plates off below the connecting strap, and sawing or punching the old plate ends out of the strap. See page 217 for instructions for welding plates to the straps.

Work on the Jars

The work on the jars consists of removing any sediment which may have collected, washing out all dirt, and replacing leaky jars. The removal of sediment and washing should be done after the preliminary charge has been given and the old electrolyte poured out unless the preliminary charge was given with distilled water in the jars. The old electrolyte need not be poured down the sewer, but may be kept in stone or earthenware jars and used later in making electrical tests to locate leaky jars.

Testing Jars