Deep cycle refilling

[MuntzAngling]

I got low levels of water in 2 of my marine batteries. At low charge do I add water without worry? I got distilled water. Just do one cell at a time, right?

[Surface Tension]

Yes you got it right. Charge that battery after you have it filled.

[Pat K]

Put just enough water in so the plates are covered. Then charge the battery.

After the battery is fully charged check the water levels and fill to the bottom of the fill tubes leaving the vent slots exposed. Then charge again.

The electrolite expands as you charge the battery, so if it's full before charging some electrolite may overflow while charging if the battery is close to fully discharged.