I want something that will Switch from powering my fridge from my Lithium Battery which is only charged from a mttp 75/15. I have a 3rd battery in the engine bay that I can currently power the fridge off as well. Since this is charged from the alternator with a dc dc charger. I want the fridge to power off this when the car is running. When I turn the car off I want it to automatically switch back over the the lithium battery. Which device from Victron will do this ?
In case anyone else one wants a solution, I came up this. Seems there is no one product to do this. I used DPDT Relay. To activate the relay I used Volt sensing controller that when the volts went up to 13.5 it let the voltage through activating the relay. On either size of the relay I had both power sources on the open and one on the close so as the relay opened closed depending on weather the care was turned on it would switch from solar battery or 2nd battery connected to a dc dc charger. This has allowed me to never have to think about it and the switch is automatic. Was very cheap to put together. Had the added luxury to 3d print my own box to house the cig 12v adaptor and the relay and VSC nicely together. Hope this helps someone since Victron don't seem to have a product todo this.
