Well I guess in my case it's not so simple.
If my batteries are isolated by a 1, 2, both, or off switch can I still maintain both (without removing all the other connections) with the single charger by simply setting the switch to BOTH. Would I still attach the positive lead to the positive terminal on one battery, and the negative to the negative on the other battery? That’s how I understand it could be done if the batteries are in parallel. Or would it work better (or at all) if I split the charger leads so that I could attach to all 4 terminal? Also, I have always turned the power off when I am not using the boat (sits on the trailer), is there any reason I should not leave the battery switch on BOTH as long as I have the battery maintainer on. Sorry for the stupid questions, but my electrical skills/knowledge pretty much sucks.