Thanks seasick and wrxhoon, I have been boating for many years with a variety of boats, never went to a sealed battery, ......just not sure why. Maybe it is time to make a change. I suppose it is potential gassing and acid spills that are the concern. Been eyeing up the Lythium batteries........a bit of an ouch on the price and do have some time left on the present ones.......one of these days.