Another way to address this would be an echo charger
, which is similar to the ACR mentioned above.
Basically, you charge Bank 1 to the desired float voltage, and Bank 2 then gets the excess.
You charge Bank 2, therefore, off the alternator
when you motor
, but reserve the ability to combine the banks if low to achieve an engine
crank OR to "switch to 1" if Bank 2 needs service
or is otherwise kaput.
I intend to have multiple charging sources and redirects to my house bank: solar
and, if necessary, genset charging. Everything goes to the house bank; if house bank is good within a preset range, juice goes to the start, and when it's at 95-100%, that is echo charged to a second deep cycle forward for the windlass
. If my house and start banks fry or are damaged, I have that windlass
battery as an "always-ready" backup.
There's combiners and isolators and switches, oh, my, but I'm heading for autonomy from shore power
. Your situation may be far more simple.