@sbhtennis - In my experience, with two 6 volt batteries, you really need a good external smart charger (Deltran Battery Tender Plus, Pro-Logix, Noco Genius, etc.). The onboard converter just would not charge my dual 6 volt batteries well at all - it's voltage output is on the low side. Measuring charge by voltage is not…
What is considered a full charge? I have 2 6 volt deep cycle type batteries connected in series. When it gets hooked up to shore power does that fully charge the battery?