Hi,
The 12.9 cut out and the 13.4 connect are why I don't think the "smart" relay is a good idea. Particularly if an inverter is in use the battery voltage may drop. At least one converter goes to 13.2 when it is in "float" mode. That means the "smart" relay will not maintain the chassis battery.
Those are some of the reasons I recommended a simple inexpensive continuous duty solenoid relay.
Arktikos wrote:
It connects batteries when it senses one of the two batteries has 13.4V available and disconnects at 12.9V. When it is connected, current can flow either direction depending on which battery has lower volts with no loss so you will charge the truck battery if the camper is plugged into shore power, on generator, or solar power..
