Originally Posted by SurfsideEd
I am thinking of installing an isolator and running a line back from the engine starting battery to my triple e battery to maintain a charge and run the fridge
while driving and use propane
or 110 while stopped, whichever might be available.
Good plan, but don't use a battery isolator that is just two diodes dividing the power. Diodes have a 0.7V drop across them.
A better, but a bit more complicated, solution is to use a relay like a starting solenoid, but rated for continuous use. Connect the coil to come on when the engine is running, (accessory circuit?). This gives you an automatic switch to disconnect power from the trailer when the TV is off.
This is also less expensive then a traditional battery isolator.