Thank you kindly for that information.
The factory Catalina 22 control panel has a "master" switch. Even with that, would I benefit from a master battery switch?
Does this master switch allow you to turn use the batteries independently? In other words, does it say "Off-1-Both-2" (or something to that effect) on it? If not, you should either get something like this:
The latter is probably over-kill for a C22, but the VSR module would let you hook the solar panel up to one battery and have it charge both (once the first one is fully charged).