I have two Group 31 Wetcell
batteries made by Interstate. I purchased one 2 years ago and another 1 year ago. They are unusual in that there is no place to add
water, as far as I can see. As the
marine store told me, they are "sealed." I paid about $100 for each. A few months ago, they discharged completely, as the
boat was on land for
winter storage and the automatic
bilge float switch got stuck in the on position. I don't know if they froze in the cold. But a week later they were down to 5 volts. I've charged them for about a total of 20 hours now and they don't go any higher than about 11.5 volts. I assume I need new
batteries.
My question is, should I buy the same kind of batteries or would I be better off with the normal wetcell batteries that I could add
water to? If had been able to add water to these, would I still need to replace them? Or could it be that my dealer was wrong and there is in fact some way to open the ones I have and add water?