Taking Batteries Out of Commission
If a battery is not to be used at all for a period not longer than about 9 months, it can be left idle if it is first treated as follows: Add sufficient water to bring the electrolyte up to the water line in all cells and then give an equalizing charge, continuing the charge until the specific gravity of each cell is at a maximum, five consecutive hourly readings showing no rise in gravity. As soon as this charge is completed, take out the battery fuse and open up one or two of the connections between cells so that no current can be taken from the battery. Have vent plugs in place to minimize evaporation.
If the battery is to be taken out of commission for a longer time than 9 months, the battery should be fully charged as above and the electrolyte poured off into suitable glass or porcelain receptacles. The plates should immediately be covered with water for a few hours to prevent the negatives heating, after which the separators should be removed, the water poured out of the jars, and the positive and negative groups placed back in the jar for storage. Examine the separators. If they are cracked or split they should be thrown away. If in good condition they should be stored for further use in a non-metallic receptacle and covered with water, to which has been added electrolyte of 1.220 specific gravity, in the proportion of one part electrolyte to ten of water by volume.