gregk9 - 11/9/2018 5:58 PM
stdevos - 11/9/2018 3:28 PM
I left mine in the boat one winter and occasionally plugged in onboard charger. In the spring found batteries dead and onboard charger swollen and cracked. Probably just a crappy charger (bargain cave variety), but now I pull everything out. Onboard charger goes in the basement and 3 batteries get rotated on battery tender in the garage.
Man, that's a lot of unnecessary work. Just get a quality onboard charger and be done with it. Make sure the batteries are topped off with water before you put the boat to bed for the winter.