I have a F-350 truck that has basically 3 battery banks.
Bank #1 is the starter batteries.
Bank #2 is a set of 2 AGM batteries that are used power a ARB fridge
Bank #3 is a set of 6 lithium batteries which are charged using the Victron Buck Boost DC-DC converter
Bank #1 is always connected to the truck alternators.
Bank #2 & #3 are isolated from the alternators via a 500Amp solenoid. The high current is necessary to allow for a large draw from the Buck Boosts.
Bank #2 & #3 are connected to the solenoid via a marine style A/B/A+B switch which allows me to charge either bank #2 or #3 or both depending on switch setting.
The issue I would like to solve is when the truck (or solenoid) is turned off and the A/B switch is set to A+B bank #2 and bank #3 are connected to each other. When this happens the AGM batteries end up charging the lithium batteries which is not good for them.
What can I use to isolate bank #2 & bank #3 when the truck is not running with out manually switching the A/B switch?
