The Automobile Storage Battery Part 49

When you sc.r.a.pe the compound from the covers, do a good job. Do not sc.r.a.pe off most of it, and then leave pieces of it here and there.

Remove every bit of compound, on the tops, edges, sides, and bottoms of the covers. If you need different sized putty knives or screw drivers to do this, use them. The time to remove all the compound is while it is still hot, and not after it has become hard and cold. If the battery has single covers, the compound can be removed very quickly. If the battery is of the old double-cover type, the job will take more time, since all the compound should be sc.r.a.ped from both top and bottom covers, Fig. 199.

[Fig. 198 Removing compound from cover]

As soon as you have removed the compound from the covers of the first cell, serape away the compound which may be sticking to the top and inside walls of the jar, Fig. 200. Here again you must do a good job, and remove all of this compound. If you do not do it now, you will have to do it when you try to put the plates back into the jar later on, as compound sticking to the inside walls of the jar will make it difficult, and even impossible to lower the plates into the jar.

Now draw up the plates of the next cell. Rest the plates on the top of the jar just long enough to drain, and then lift off the covers, and remove all of the compound, from cover, posts, and jar, just as you did in the first cell. The third cell, (and the others, if there are more than three cells) are handled just as you did the first one.

Remember that you should lose no time after you have steamed the battery. Hot compound is soft and does not stick to the covers, jars, and posts and may therefore be removed quickly and easily. Cold compound is hard, and sticks to the covers. Draw out the plates of only one cell at a time, and clean the compound from the cover, posts and jar of that one cell before you draw out the plates of the other cells. In this way, the compound on the covers of the other cells will remain hotter than if all the plates of the battery were drawn out of the jars before any of the compound was removed from the covers. You should have all the plates drawn out, and all the compound removed within five minutes after you draw up the plates.

[Fig. 199 Removing sealing compound from double cover]

Throw away the old compound. If is very likely acid-soaked and not fit for further use.

What Must Be Done with the Battery?

The battery is now open, and in a condition to be examined and judgment p.r.o.nounced upon it. The question now arises, "What must be done with it!" In deciding upon this, be honest with your customer, put yourself in his place, and do just what you would like to have him do if he were the repairman and you the car owner. The best battery men occasionally make mistakes in their diagnosis of the battery's condition, and the repairs necessary. Experience is the best teacher in this respect, and you will in time learn to a.n.a.lyze the condition of a battery quickly.

Handle every cell of a battery that comes in for repairs in the same way, even though only one dead cell is found, and the others are apparently in good condition. Each cell must be overhauled, for all cells are of the same age, and the active materials are in about the same condition in all the cells, and one cell just happened to give out before the others. If you overhaul only the dead cell, the others cells are quite likely to give out soon after the battery is put into service again.

[Fig. 200 Removing compound from top of jar]

It is absolutely necessary for you to have a standard method in working on battery plates. You must divide your work into a number of definite steps, and always perform these steps, and in the same order each time. If you have a different method of procedure for every battery, you will never be successful. Without a definite, tangible method of procedure for your work you will be working in the dark, and groping around like a blind man, never becoming a battery expert, never knowing why you did a certain thing, never gaining confidence in yourself.

It is impossible to overemphasize the importance of having a standard method of procedure and to stick to that method. Careless, slip-shod methods will please your compet.i.tor and give him the business which belongs to you.

1. Examine plates to determine whether they can be used again Rules for determining when to discard or use old plates follow.

2. If all plates of both positive and negative groups are to be discarded, use new groups.

The question as to whether the old negatives should be used with new positives has caused considerable discussion. If the negatives are old and granulated, they should of course be discarded. Remember that the capacity of negatives decreases steadily after they are put into service, while the capacity of positives increases. Putting new positives against negatives which are rapidly losing capacity is not advisable. However, trouble often arises in a battery whose negatives still have considerable capacity, and such negatives may safely be used with new positives.

If you feel that a battery will not give at least six months more service after rebuilding with the old negatives, put in all new plates, or sell the owner a new battery, allowing him some money on the old battery. But if you really believe that the negatives still have considerable capacity, put in new positives if required. If all new plates are used, proceed as directed in this chapter, beginning at page 348.

3. If you find that only some of the plates are to be discarded, or if you are not certain as to the condition of the plates, eliminate any short circuits which may exist, and give the battery a preliminary charge, as described later, before you do any work on the plates.

Plates that are fully charged are in the best possible condition for handling, and you should make it an ironclad rule that if some of the plates can be used again always to charge a battery before you work on the plates, no matter what is to be done to them. If both positives and negatives are to be discarded, the preliminary charge should not, of course, be given, but if only the negatives, or the negatives and some or all of the positives are to be used again, give this preliminary charge. Very few batteries will come to your shop in a charged condition, and an exhausted battery is not in a good condition to be worked on. Charge the whole battery even though only one cell is in a very bad condition. This is a method that has been tried out thoroughly in practice, not in one or two cases, but in thousands.

Batteries in all sorts of conditions have been rebuilt by this method, and have always given first cla.s.s service, a service which was frequently as good, if not better than that given by new batteries.

Examining the Plates

Place an element on a block of wood as shown in Fig. 201. Carefully pry the plates apart so that you can look down between them and make a fair preliminary examination. Whenever possible, make your examination of the plates without separating the groups or removing the old separators. This should be done because:

(a) Very often the active material is bulged or swollen, and if you pull out the old separators and put in new ones before charging, the element spreads out so at the bottom that it cannot be put back into the jars without first pressing in a plate press. Pressing a complete element with the separators in place should never be done if it can possibly be avoided. If it is done the separators should be thrown.

away after you have charged the battery, washed and pressed the negatives, and washed the positive.

[Fig. 201 Element on block for examination]

(b) If you put in new separators before giving the battery the preliminary charge, the new separators may pick up any impurities which may be on the plates, and will probably be cracked by forcing them between the bulged and sulphated plates. If, however, the old separators are covered with sulphate, it is best to throw them away and put in new separators before giving the battery its preliminary charge, because such separators will greatly hinder the flow of the charging current. In batteries using rubber sheets in addition to the wooden separators, remove all the wooden separators and leave the rubber sheets in place between the plates. Where only wooden separators are used in a battery, these may be thrown away and perforated rubber separators used for the preliminary charge. Rubber separators may be used again. See (a) above about precautions against pressing a complete element.

[Fig. 202 Separating the groups]

If you are not absolutely certain as to the condition of the plates, draw out a few separators. If separators stick to the plates, loosen them by inserting a putty knife blade between them and the plates.

Removing a few separators will permit you to separate the groups before removing the rest of the separators. To separate the groups, grasp a post in each hand, as, in Fig. 202, and work them back and forth, being careful not to injure the posts, or break off any plates.

With the groups separated, the remaining separators will either fall out or may be easily pushed out with a putty knife. Ordinarily, the groups may be separated in this way if the elements have thirteen plates or less.

The natural thing to do at this point is to decide what must be done to the plates, and we therefore give a number of rules to help you determine which are to be junked, and which are to be used again.

Study these rules carefully, and have them fixed firmly in your mind so that you can tell instantly what must be done with the plates.

[Fig. 203 Positives from frozen vehicle cell, showing active material sticking to separator]

When to Put In New Plates

1. If one or more jars are cracked and leak, and positive plates have been ruined by freezing, as shown in Fig. 203, and if upon drawing out the separators, and separating the positive and negative groups the active material drops out of the grids, the only way to put the battery in a good condition is to put in new positives, and new jars and case if necessary.

Make a careful estimate of

1. (a) Cost of new jars.

2. (b) Cost of new plates.

3. (c) Cost of new case if needed.

4. (d) Cost of labor required.

Try to have the owner present while you are opening his battery. If, however, he could not wait, and has left, call him up and tell him what the total cost will be, and if he has no objections, go ahead with the job. If he is not entirely satisfied with your price, try to get him to come to your shop. Show him the battery, explain its condition, tell him just what must be done with it, and explain how you made your estimate of the cost of the whole job. If you do this.

there will never be any misunderstanding as to cost. Tell him the cost of a new battery, and let him decide if lie wants one. If the cost of repairing is almost as much as the price of a new battery. advise him to buy a new one, but allow him to make the decision himself. He will then have no cause for complaint.

[Fig. 204 and 205 Show Diseased Negatives. The Large Ones Only Eight Months Old. Active Material, Granulated and Blistered]

2. If the battery is more than two years old, and the active material on the negative plates is granulated (grainy appearance), Figs. 204 and 205, and somewhat disintegrated; if the plates are weak and brittle around the edges, and several grids are cracked, Fig. 206, and the plates have lost a considerable amount of active material; and if the case has been rotted by the acid, the battery should be junked.

[Fig. 206 Weak and cracked positives]

Call up the owner, and tell him he needs a new battery. If he does not seem pleased, ask him to come to your shop. Then show him his battery, and explain its condition. If you are courteous and patient, you will sell him a new battery. Otherwise he will never return.

[Fig. 207 Buckled plates, and Fig. 208 An unusually bad case of buckling]

3. If the positive plates are badly distorted from buckling, as in Figs. 207 and 208 discard them, for they will cut through new separators, if put into commission again, ill from two to six months.

4. A battery which has has been dry and badly sulphated at some past period of its life will have the dry portions covered with a white sulphate, the acid line being clearly distinguishable by this white color, as shown at A and B in Fig. 201. If the plates are otherwise in good shape and you wish to use them, give them the "water cure"

described on page 349.

[Fig. 209 Corroded, bulged and sulphated negatives.