Whatever you do, be sure to isolate one battery as being your engine
start battery. That's why you have two or three circuits on your control panel
. The usual circuits are 1. Domestic, 2. Engine, and 3 (If you have them) Auxiliary batteries.
You can trace the individual circuits from your (Probably Three) Battery Islolater switches, just follow the cables
from those switches and you should be able to find your way around. BUT, as I said before, make sure that your engine start battery is on a seperate circuit; Why? That's because if you run your domestic batteries flat, you will still be able to start your engine. And further, you should consider adding at least one extra battery to your domestic service
circuit, even more if you plan to be sailing offshore
. The typical set up for off shore sailboats would be for One engine start battery and Three 100 AH domestic batteries PLUS either a wind
turbine, solar panels
, or both of those things.
If you will only be doing short trip coastal sailing, you could get away with less than that but if you plan to go off into the wild blue yonder, what I have described above would be the Minium
you would go with. Hope this helps, Safe sailing to you, James