Can you use filtered water in a car battery?

It is not advisable to use filtered water in a car battery. While filtered water is generally free of impurities, it may still contain minerals, sediments or other dissolved substances that could affect the battery's performance or longevity.

Distilled water or deionized water is specifically recommended for car batteries because it is nearly pure and free from minerals that could potentially build up inside the battery plates, leading to issues with charging and eventually damaging the battery's internals.