I am about to add 2 - 6v Golf Cart batteries, wired in parallel, to
form a separate house bank.
I have a twin-engined boat with a generator and a 110v AC/DC smart
battery charger.

I know that connecting two 110v AC sources is a no-no. A shore/gen.
selector switch renders this almost foolproof.
However I have the possibility of connecting three different 12v DC
charging sources together.

I have various manufactures (mainly Blue Seas Systems) circuit diagrams
showing how to hook-up individual components. None show how to wire-up
a system with multiple components incorporated.
My intent is to be able to charge: the engine start batteries, the
generator start battery and the house batteries from any/all of the
various sources, but preventing one source from smoking another if they
are running concurrently.
e.g Shore power off, engines running, generator running which means
battery charger is outputting a charge.
The alternators will be fitted with smart regulators and the battery
charger will be 'smart' with three outputs. All batteries will be "wet"
Also need to hook-up a battery isolation/paralleling switch. Again,
literature only shows 2 batteries!

Does anyone know of any good books that would describe/diagram how to
hook-up all the various components to form a safe, modern 12v DC
system? (ABYC manuals at $120 each apart)

I don't want to have to run around here, there and everywhere flipping
switches only to forget one and smoke the whole system.

Thanks,

David Morton