Kiron Rithe

Right then. You use distilled water because it's completely pure H2O. Your regular tap water is full of minerals and other impurities. These minerals can build up on the battery's internal lead plates, messing with the chemical reaction. This reduces the battery's ability to hold a charge and seriously shortens its lifespan. Using only distilled water keeps the chemistry clean and ensures your battery lasts as long as it should. It's cheap insurance, mate.