mrad wrote:
Yesterday I brought in my two deep cycle batteries from my boat and the one from my camper for winter storage. I check all of the water levels and had ended up adding some distilled water to each, bring it to just under a 1/4" from the top.
So far all three batteries have overflowed during charging. What else could be the cause of this?
I have never experienced this problem before.
Any Ideas?
When wet cell batteries charge, it is normal for the electrolyte and the other internal components (plates, separators, connectors, etc.) to heat up which causes them to expand. The electrolyte also will off gas. (hydrogen and oxygen) If you overfill the electrolyte, the additional gas has no place to go since you have blocked the vents. As the state of charge of the batteries increases, solid precipitate from the plates dissolves back into the electrolyte causing its volume to increase slightly also with no place to go but out the fill holes. Some charge cycles cause water to evaporate out the fill holes which can (not always) off set this. Someone else pointed out that the time to fully top off the water is AFTER you are done charging, as long as the plates are covered (about 1/8 to 1/4 inch) with electrolyte prior to charging. DO NOT CHARGE A WET CELL BATTERY IF ANY PORTION OF THE PLATES ARE DRY!
Chum lee
