Battery Type AGM

[joshmon71]

Sears Platinum group 31 duals for me. Single OB. Sears Platinum 31=Odyssey. They go on sale on occasion.

BEP cluster for isolation with a voltage relay. http://www.bepmarine.com/home-mainmenu-8/product-278/ This rocks. No more switching manually to charge each battery and that non sense.

"The VSR allows for two batteries to be charged at the same time. When the engine is started, and the start battery reaches 13.7 Volts, the relay closes, Combining the battery banks (start and house) and allowing them to be charged
simultaneously. When the engine is stopped and the voltage drops to 12.8 Volts, the relay will open separating the batteries. This system eliminates the possibility of draining the wrong battery and protects sensitive electrical equipment powered from the house battery from harmful engine start up spikes." from mnual http://www.bepmarine.com/media/produ...73148082df.pdf

I also have a battery charger/tender rated for AGM, but forget the brand and name. Boat is about mile away can look if want.

I'd put a volt meter on your batter tender, it does seem like that might be a probable issue. You will know soon enough though . I have left my dual AGM Sears Plat 31 batteries in the boat all winter and season now for 5th year.

Never an issue.