"Bill Kearney" wrote in
:

Can I just add this new bank in parallel to the existing ships system
battery? Do I need to add another isolator? Can I hang that isolator
off the current isolator? As in pull one leg off the existing 2/3
isolator and split it via another 1/2 isolator. Or do I "have to" use
a whole other 2/2 isolator?


Anytime you are charging, with any charger, all they need is to all be in
parallel and the batteries will sort out how much current each branch of
them wants to charge with. Battery chargers are voltage floating devices
for lead-acid batteries.

My suggestion is to add another A-B-BOTH-OFF battery switch to the
existing house battery + terminal. Remove the + cable from the house
battery and connect it to the common terminal on the switch. Now, add a
heavy jumper from A to the original house battery and from B to the new
monster golf cart series batteries. This switch allows you to isolate
and bad or just dead batteries from the live ones you're running the boat
off of until you can get bad batteries replaced or dead batteries
charged. Under usage, charging or discharging, leave the switch in BOTH
to parallel the banks, or you can discharge them one-at-a-time in A or B.

The charging connection should still be hooked to the common terminal on
the new switch, by default. If you're going to store it on the hook for
over a day or so, pick a battery bank, A or B, to leave the house on,
which isolates them when there's no charging. Hook the automatic bilge
pumps, of course, to the biggest battery bank, DIRECTLY not through an
panel or switches where it can be cut off with a separate fuse double in
size to the load of the pump lifting lots of water. Bilge pumps should
NEVER have OFF positions!....that includes those damned RULE pump
switches with the crappy pushon connectors that belong in the dumpster!

Larry
--
http://www.spp.gov/
The end of the USA and its Constitution....RIP