There is much to be said about shore power & a charger.
Just replaced my 2 group 31s, they were original to the boat (10 years old)
The boat is plugged in year round, at the slip and at home when I haul out in dec.
Old batteries still held a charge but figured why push my luck.
Marine batteries are classed by group,
Group 24, 27, 29, 31
31 is equivalent to a 8D battery in a tractor trailer .
Most production boats come with group 24
|