Hence, it is necessary to periodically inspect the level of electrolyte in the battery. If the level of the electrolyte falls below the minimum level, it can be topped up by adding water. Only distilled water should be added as ordinary water may contain a lot of impurities and ions which may contaminate the electrolyte.
The acid used as the electrolyte is extremely corrosive and should be handled with extreme care. Proper protective outfits should be worn while handling them. Water can be added to a container of acid. However, acid can never be added to container of water as the heat generated can cause splashing.