Fig. 1,167.—Illustrating method of placing plates in glass jars.
Ques. What should be done in case of sulphation?
Ans. Charge the battery below the maximum rate, necessarily prolonging the charge, until the plates assume the proper color. This is a tedious task, but it must not be hastened, as rapid charging will cause serious buckling.
NOTE.—How to destroy acid vapor in storage battery rooms: The best remedy is a good system of thorough and rapid ventilation; failing this the evil effect of the acid may be minimized by the fumes of a powerful alkali such as ammonia, which will readily combine with the sulphuric acid to form sulphate of ammonia, an inert and harmless salt. If the use of liquid ammonia be objectionable, the granulated carbonate of ammonia will do equally well. The ammonia fumes are best obtained by placing dilute ammonia in shallow dishes, so that an extensive evaporating surface is obtained. In the same way the corroding dew which is so frequently deposited on the lugs and connectors of storage battery elements may readily be neutralized by the application of a solution of ammonia, or even common washing soda. A good method of protecting metal work in battery rooms is to smear it over evenly with vaseline.
The charging should be done at low rates. Discharge should not be carried below 1.8 volts per cell, and the charging current should be stopped when each cell shows 2.4 volts.
If the plates be in a very bad condition, a little of the white sulphate deposit on each of the positive plates may be removed with a stick, thus exposing a part of the good surface to the action of the electrolyte.
If the positive plates cannot be restored to their proper color as directed, it is cheaper to replace them by a new set, rather than to attempt their recovery by means of reversals.
| Number of Plates per cell | 5 | 7 | 9 | 11 | |
|---|---|---|---|---|---|
| Discharge in amperes | {for 4 hours | 12 | 18 | 24 | 30 |
| {for 5 hours | 10¼ | 15¼ | 20½ | 25½ | |
| {for 6 hours | 9¼ | 13¾ | 18½ | 23 | |
| Ampere hour capacity | {at 4 hour rate | 48 | 72 | 96 | 120 |
| {at 5 hour rate | 51 | 76 | 102 | 127 | |
| {at 6 hour rate | 55 | 83 | 110 | 138 | |
| Outside measurements of rubber jar, in inches | {Length | 1⅞ | 2⅝ | 3⅜ | 43/16 |
| {Width | 55/16 | 55/16 | 55/16 | 55/16 | |
| {Height | 11¾ | 11¾ | 11¾ | 11¾ | |
| Weight of cell complete, in lbs | 14¼ | 19¼ | 24¼ | 29¾ | |
| Weight of electrolyte, in lbs | 1 | 2 | 3½ | 5 | |
Lack of Capacity.—This is usually due to the clogging of the pores in the plate with sulphate which is invisible because the surface of the plate is maintained in proper condition but the interior portions of the active material have not been thoroughly reduced. To correct this condition, the battery should be given a prolonged overcharge at low current rates, say about one fourth the normal 8 hour charging rate.
NOTE.—Oxide of lead, litharge, or plumbic oxide is sometimes found native as lead ochre, and may be artificially made by heating the carbonate or nitrate. It is usually prepared on a larger scale by heating the lead in air. When the metal is only moderately heated, the oxide forms a yellow powder which is known as massicot, but at a higher temperature the oxide melts, and on cooling, it forms a brownish scaly mass, which is called flake litharge. The scaly pieces are afterwards ground between stones under water, forming buff or levegated litharge. The litharge of commerce often has a reddish yellow color, due to the presence of some of the red oxide of lead, and frequently from one to three per cent. of finely divided metallic lead is found mixed with it. When heated to dull redness litharge assumes a dark brown color, and becomes yellow again on cooling. At a bright red heat it fuses and readily attacks clay crucibles, forming silicate of lead. Litharge is a most powerful base, and has a strong tendency to form basic salts. Hot solution of alkalies, as potash or soda, readily dissolve it, and on cooling, it crystalizes out in the form of beautiful pink crystals.