The Automobile Storage Battery Part 50

Disintegrated, rotten positives.]

[Fig. 210 Disintegrated positives.]

5. Rotten and disintegrated positive plates, Figs. 209 and 210, must be replaced with new plates. The plates have fallen to pieces or break at the slightest pressure. Disintegrated plates are an indication of impurities or overcharging, providing the battery is not old enough to cause disintegration normally,--say about two years. The lead grid is converted into peroxide of lead and becomes soft. As a result, there is nothing to support the paste, and it falls out. Better put in new negatives also.

6. Batteries with high gravity or hot electrolyte have burned and carbonized separators, turning them black and rotting them, the negative paste becomes granulated and is kept in a soft condition, and gradually drops from the grids on account of the jolting of the car on the road. Fig. 211 shows such a battery.

7. Dry, hard, and white, long discharged, and badly sulphated plates, Figs. 201 and 209, are practically ruined, though if the trouble is not of long standing, the plates may be revived somewhat by a long charge at a very low rate, using distilled water in place of the electrolyte, and then discharging at a current equal to about one-eight to one-tenth of the ampere hour capacity of the battery at the discharge board. Charge and discharge a battery a number or times, and you may be able to put a little "pep" into it. In charging sulphated plates, use a low charging rate, and do not allow ga.s.sing before the end of the charge, or a temperature of the electrolyte above 110F.

[Fig. 211 Side and end view of element from traveling salesman's battery]

8. If a battery case is not held down firmly, or if the elements are loose in the jars, the plates will jump around when the car is in motion. This will break the sealing compound on top of the battery, and cause the battery to be a slopper. The active materials will be shaken out of the grids, as shown in Fig. 212, and the plates will wear through the separators. New plates are required.

9. If Battery Has Been Reversed. Often the plates of such a battery disintegrate and crumble under the slightest pressure. If the reversal is not too far advanced, the plates may be restored (See page 81), but otherwise they should be discarded. This condition is recognized by the original negatives being brown, and the original positives gray.

From the foregoing explanations, you see that most of the trouble is with the positives:

(a) Because the positive active material does not stick together well, but drops off, or sheds easily.

(b) Because the positives warp or buckle, this causing most of the battery troubles.

(c) Because the positive plate is weaker and is ruined by freezing.

When the Old Plates May be Used Again

1. If one or more plates are broken from the plate connecting straps, or the joint between any strap and the plate is poorly made. If plates are in good condition, reburn the plate lugs to the straps.

[Fig. 212]

Fig. 212. Element from a "Slopper." Element was Loose in Jar and Jolting of Car Caused Paste to Fall Out.

2. Straight Rebuild. If the general condition of the battery is good, i.e., the plates straight or only slightly buckled, only a slight amount of shedding of active material, no white sulphate oil either plate, the grids not brittle, active material adhering to and firmly touching the grids, the positive active material of a dark chocolate brown color and fairly hard (as determined by scratching with blade of a pocket knife), the negative active Material dark gray in color and not blistered or granulated, and the plates not too thin, make a straight rebuild. To do this, charge the battery, remove any sediment from the bottom of the jar, wash and press the negatives, wash the positives, clean the parts, insert new separators, and rea.s.semble as directed later. The only trouble may be cracked sealing compound, or a broken jar. Broken jars should, of course, be replaced.

[Fig. 213 Badly bulged negatives. Such plates must be pressed]

3. Badly bulged negative plates, Fig. 213, cause lack of capacity because the active material is loose, and does not make good contact with the grids. If the active material is not badly granulated (having a grainy appearance) the plates call be used again. Sulphated negatives have very hard active material, and will feel as bard as stone when scratched with a knife. Hard negatives from Which active material has been falling ill lumps Oil account of being overdischarged after having been in in undercharged condition may be nursed back to life, if too much of the active material has not been lost.

4. The formation of an excessive amount of sulphate may result in cracking the grids, and the active materials falls out in lumps. Such plates may be put in a serviceable condition by a long charge and several cycles of charge and discharge if there is not too much cracking or too much loss of active material.

5. Positives which are only slightly warped or buckled may be used again.

6. When the only trouble found is a slight amount of shedding.

Positive active material must be of a dark chocolate brown color and fairly hard. Negatives must be a dark gray.

7. When the plates are in a good condition, but one or more separators have been worn or out through, or a jar is cracked.

If the battery is one which will not hold its charge, and plates seem to be in a good condition, the trouble is very likely caused by the separators approaching the breaking down point, and the repair job consists of putting in new separators or "reinsulating" the battery.

What To Do With the Separators

It is the safest plan to put in new separators whenever a battery is opened, and the groups separated. Separators are the weakest part of the battery, and it is absolutely essential that all their pores be fully opened so as to allow free pa.s.sing of electrolyte through them.

Some of the conditions requiring new separators are:

1. Whenever the pores are closed by any foreign matter whatsoever. Put in new separators whether you can figure out the cause of the trouble or not. The separator shown in Fig. 201 is sulphated clear through above the line B, and is worthless. The separator shown in Fig. 203 should not be used again.

2. When the separators have been cut or "chiseled off" by the edge of a buckled plate, Fig. 214.

3. When a buckling plate or plate with bulged active material breaks through the separator, Fig. 214.

[Fig. 214]

Fig. 214. Separators Worn Thin and Cut Through on Edges by Buckled Plates. Holes Worn Through by Bulged Active Material, Center One Shows Cell Was Dry Two Thirds of the Way Down.

4. When a battery has been used while the level of the Fig. 214.

Separators Worn Thin and Cut Through on Edges by Buckled Plates. Holes Worn Through by Bulged Active Material. Center One Shows Cell Was Dry Two Thirds of the Way Down electrolyte has been below the tops of the plates, or the battery has been used in a discharged condition, and lead sulphate has deposited on the separators, Fig. 201.

[Fig. 215 Rotted separators]

5. When a battery has been over-heated by overcharging or other causes, and the hot acid has rotted, burned and carbonized the separators, Fig. 215.

6. When a battery has been damaged by the addition of acid and the separators have been rotted, Fig. 215.

7. Separators which are more than a year old should be replaced by new ones, whether plates are defective or not.

When you have put in new separators, and put the battery on charge, the specific gravity of the electrolyte may go down at first, instead of rising. This is because the separators may absorb some of the acid.

If the battery was discharged when you put in the new separators, the lowering of the specific gravity might not take place, but in most cases the specific gravity will go down, or not change at all.

Find the Cause of Every Trouble

The foregoing rules must be studied carefully and be clearly tabulated in your mind to be able to tell what to put into commission again and what to discard as junk. It will take time to learn how to discriminate, but keep at it persistently and persevere, and as you pa.s.s judgment on this battery and that battery, ask yourself such questions as: What put this battery in this condition? Why are the negative plates granulated? Why are the positive plates buckled? What caused the positive plates to disintegrate? Why are the separators black? Why is the case rotten when less than a year old? Why did the sealing compound crack on top and cause the electrolyte to slop? Why did one of the terminal connectors get loose and make a slopper? Who is to blame for it, the car manufacturer, the manufacturer of the battery, or the owner of the car? Why did this battery have to be taken off the car, opened up and rebuilt at 5 months old, when the battery taken off a car just the day before had been on for 30 months and never had been charged off the car but once? There is a reason; find it. Locate the cause of the trouble if possible, remove the cause; your customer will appreciate it and tell his friends about it, and this will mean more business for you.

Eliminating "Shorts"

If you have decided that some or all of the plates may be used again, the next thing to do is to separate any plates that are touching, and put the battery on charge. It may be necessary to put in new separators in place of the defective ones. Examine the separators carefully. Whenever you find the pores of the separators stopped up from any cause whatsoever, put in new separators before charging.

1. Sometimes the negative plates are bulged or blistered badly and have worn clear through the separators, Fig. 214, and touch the positives. In cases of this kind, to save time and trouble, separate the groups, press the negatives lightly, as described later, a.s.semble the element with new separators, and it is ready for charging.

2. There is another case where the groups must be separated and new separators inserted before they will take charge, and that is where the battery has suffered from lack of water and has sulphated clear through the separators, Fig. 201. The separators will be covered with white sulphate. Chemical action is very sluggish in such cases.