Re: Best way to care for a 12V battery?

[Don]

Sounds like you have tried to take care of your boat’s battery, might just be bad luck.
Like everyone has said, a nice slow charge (2 amps) a few times during the winter should maintain a good battery. Make sure the cells are filled properly with distilled water before charging, then clean the battery off with soapy water after the charge. A dirty battery can possibly create its own short circuit between the terminals helping it drain down prematurely as well.