Flooded lead-acid golf cart batteries use water. AGM batteries and lithium batteries do not. If the caps unscrew and you can see liquid, the battery is flooded and it needs distilled water. If the case says AGM or sealed, leave it closed.
When to add water
Charge the pack first, then water it. Charging raises the level. If you fill a low battery before charging, acid can overflow once the charge finishes. Check monthly in Florida heat, and any time the cart sits in storage.
How much water
Wear glasses and gloves. Pry the caps off with a cap tool, not a screwdriver that can crack them. Add distilled water until the plates are just covered, usually about a quarter inch under the bottom of the fill well. Tap water leaves minerals on the plates. Do not use battery acid to top off a battery that only needs water.
Overfilling pushes acid out of the vent and onto the tray, which eats cables and the cart frame. Underfilling exposes the plates and permanently cuts capacity.
After you close the caps
Wipe the tops dry so the case does not track current between the posts. If one battery in the pack is always thirsty and the others are not, that battery is the weak one. Replace the whole set rather than one battery. Shop flooded golf cart batteries or a complete set.
