I have had a Super Maramu (#195) for 10 years, currently hauled out
in Deltaville, VA. Before that, a Maramu for 13 years. I have stored
these boats hauled out in the US and Europe many of the winters. I
NEVER left a boat plugged in for the winter. The batteries always did
fine. (I turn off ALL power-drawing items) My batteries have lasted 5 -
8 years. I have always used the Delco sealed batteries (original Amel
equipment), but other batteries should also do fine over the winter.
If a battery charger trips a circuit breaker, the problem is a
short somewhere in the system, or a faulty charger. Boat yard
electrical systems are notoriously poor. Unless you are living aboard,
don't leave your boat plugged in. It's not a good idea.
Roy, Excalibur (SM #195)