Many replacement batteries are of the maintenance free type. For these batteries, follow the procedures described earlier. If the replacement battery you have purchased is not a maintenance free type, follow these easy procedures.
Check the battery fluid level at least once a month, more often in hot weather or during extended periods of travel. The electrolyte level should be up to the bottom of the split ring in each cell. If the level is low, add water. Distilled water is best for this purpose, but ordinary tap water can be used in a pinch.
At least once a year, check the specific gravity of the battery with a hydrometer. It should be between 1.20–1.26 on the hydrometer's scale. Most importantly, all the cells should read approximately the same. If one or more cells read significantly lower than the others, it's an indication that these low cells are going bad. Replace the battery.
If water is added during freezing weather, the vehicle should be driven several miles to allow the electrolyte and water to mix. Otherwise the battery could freeze.
Batteries should be checked for proper electrolyte level at least once a month or more frequently. Keep a close eye on any cell or cells that are unusually low or seem to constantly need water — this may indicate a battery on its last legs, a leak, or a problem with the charging system.
Top up each cell to the bottom of the split ring, or, if the battery has no split ring, about 3⁄8 in. (9.5mm) above the tops of the plates. Use distilled water where available, or ordinary tap water, if the water in your area isn't too hard. Hard water contains minerals that may slowly damage the plates of your battery.