Part 50 (1/2)

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.