[rpmerf]

When I setup my dual battery setup, I plan to have one battery give the main feed to the starter and receive a charge from the voltage regulator through a diode so it will not be able to discharge into the other battery. The other battery will be for the rest of the truck..lights, ignition, radio. I will run a switch so I CAN use starter battery for running the rest of the car if I need to. A diode seems to make much more sense than a relay for this application. I would like to see the logic of this relay, do you have a part number?

EDIT: I think I get it now. It was confusing seeing that relay with 3 pos inputs, but I guess when the ignition is on, the wire that goes in the cab outputs voltage which connects the 2 batteries together. Total genius!

EDIT AGAIN: Just went out to the truck, the in cab wire always sees voltage so ??? maybe something is funky with my wiring?