I have the 7622 with the manual 3 position rocker switch. Works well for our setup. It is in the off position all of the time since we have lots of solar. Parked in the shop I can plug in the camper charger and switch the rocker to lock both banks together and charge also the truck battery. All batteries are AGM.
I have the option while camping IF solar is not keeping up to use the alternator to help bring up the camper batteries. Good for jump starting if truck battery is dead.
If I had lithium in the camper I would remove it and install DC to DC charger with a rocker switch to work the same way.
Now I can see if I wanted to use the 7622 until time would alow to install a DC to DC unit here is a thought.
Get the three way rocker switch. Install it in a convenient place in the cab. While driving have the system in auto. When turning off the engine switch the rocker to turn off position so that the two banks of batteries don't see each other.
Years ago rando posted how to use the units ground wire as a switch.
But I would just get the DC to DC charger installed and move forward with one less thing to fiddle with. Cheers...
Edited by pvstoy, 31 October 2022 - 12:34 AM.