The Automobile Storage Battery: Its Care And Repair

by Otto A. Witte

Threaded Rubber Insulated Batteries received bone-dry must be prepared for service, as follows:

1. Mix electrolyte to a density of 1.275.

2. Remove the vent plugs and fill to the top of the vent hole with 1.275 electrolyte. Be sure that the electrolyte is thoroughly mixed by stirring and that its temperature is not above 90 degrees Fahrenheit.

3. A portion of the solution will be absorbed by the plates and insulation because they have been standing dry without any liquid in the cells. The volume is thus decreased, necessitating the addition of electrolyte after first filling.

Wait five minutes and then again fill to the top of the vent hole with 1.275 electrolyte.

4. The battery must now stand at least twelve hours and not more than twenty-four hours before charging. After it has been filled an increase in temperature of the battery solution will take place. This is caused by the action of the acid in the solution penetrating the plates mid reacting with the active material, but does no injury. Since the acid in the solution joins the active material in the plates the density of the solution becomes proportionately lower. This is to be expected and should cause no concern.

In order that the entire plate volume of active material may be in chemical action during charge, the battery should stand before being placed on charge—until the solution has bad time to penetrate the entire thickness of the plates. This requires at least twelve hours, but not more than twenty-four hours.

5. Just before charging the battery, again fill with 1.275 electrolyte to 3/8 inch over the top of the separators. After this, do not add anything but distilled water to the battery solution.

6. The battery should then be put on charge at the finish rate until the gravity stops rising. At the end of this period the specific gravity should be between 1.280 and 1.300. It may take from 36 to 72 hours before this density is reached.

Care should be taken not to prolong the charging unduly, for that may cause active material to fall out of the grids, thus injuring the plates beyond repair.