Stephen Trapani wrote in news:IxjTf.91
:

So my AC charger is a West Marine 5 amp. Alternator is a 60a which puts
out 35a. I (will) have two 6V T105s in series on BANK2 and a Kirkland
900cca starting battery on BANK1. I connect both charging sources to
BANK2 either on the battery switcher BANK2 post or right on the BANK2
batteries.

I can charge both banks at the same time by putting the switch on BOTH
and don't have to worry about the starting battery getting overcharged
because even if it is mostly charged and BANK2 is almost dead, both
banks will only get what charge they need on the BOTH setting?



It'll work great. If the alternator is directly connected to the Bank 2
batteries, either at the battery or the post, moving the switch won't blow
anything as the alternator is always hooked to a battery. The batteries
will charge themselves. The little recharge on the starting battery won't
even start until the parallel connected house battery load allows the
alternator voltage to rise up above the starting battery's current
voltage....It'll be fine.

Don't forget to switch from the BOTH position as soon as you shut down the
engine, though....