If your trolling motor battery was accidently submerged in about ten feet of
water for about 15 minutes, would it cause it any harm? It's not sealed it
has caps

The water probably diluted the acid pretty bad, especially if it was fully
charged. If it was charged I would drain it and refil with new acid - used to
be able to get it an auto parts stores, not sure any more. If it was discharged
you also lost a lot of the lead that was in the acid, so that is a bigger
problem, but all you can do is drain and fill with new acid and hope.

If the battery was charged, test it before doing anything and see what its
specific gravity is. If still good, the acid probably did not get diluted.
Ronnie

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