De-Ionised (DI) water is what’s typically used for engine batteries for several reasons. Because the DI water is purer that distilled water, it minimises the formation of mineral deposits in batteries. This is especially true in automotive as the heat can speed up the process of calcification. This in turn leads to poorer battery performance and life.

The use of de-ionised water when maintaining batteries can help to prolong the service life of your battery system.