Info needed for Dual Battery system.



My question is this. Does the factory installed dual battery system incorporate battery isolation? Also with the dual battery comes 2 alternators that have different capacities. Do the alternators feed a DC Main bus in parallel or are they switched somehow?

I see a box next to the main batter to which several large gauge cables are connected, but I have not dissected it to see what it does. I am curious to know how max power can be drawn from the system by the winch or some other heavy load, maybe an inverter or welder.

Any information you can provide is appreciated. I have not found much on the net.