Most people deal with lead acid batteries as 12-volt batteries in their cars. Lead acid batteries consist of an acid-resistant casing surrounding lead grids. Actually, a 12-volt battery is six, two-volt batteries connected together in one case. These batteries generate electricity when the acid reacts with the lead. The reaction changes the acid into water. Charging the battery removes chemicals from the lead and turns the water back into acid. Sometimes the water will evaporate out of the battery. Water then must be added back to the battery so that the chemical process can continue to happen to maintain power in the battery.
Put on safety glasses and work gloves. Loosen the cap that seals the battery chambers by pushing a screwdriver under the edge of the cap and prying upward. Be careful in this process not to break the cap. Try not to lift the cap too quickly because it can cause acid to splash onto surrounding surfaces or your skin.
Lift the loose cap up and away from the battery. Most of the time, one cap will cover three chambers. Repeat the process of removing the cap on the other end of the battery. Look into each of the battery's chambers to check the acid level. The level should be at the bottom edge of the opening where the cap inserts into the battery. If any of the lead core is exposed, the battery is very low on acid. In a good battery, refilling the chambers with water is all that is necessary to keep it working properly.
Open a bottle of distilled water to use to fill the lead acid battery. If the mouth of the bottle is large, pour the water into a container more suited for pouring into the battery. Pour the water slowly into each low chamber until the level reaches the lower edge of the opening for the cap.
Set the cap onto one end of the battery so that the caps for each chamber line up with the openings. Push down on the upper side of the strip until all of the caps are in place. Repeat this process for the strip on the other end of the batter. Remove work gloves and safety glasses.
