We set our fridge to Auto mode so it's running off propane (our unit cools better in this mode) anytime we're not plugged into shore power. Our only precaution Is to turn off fridge while refueling. To run directly off battery power while driving your fridge would need a 12VDC mode. Many have reported that contents will stay cold for some time with fridge off. I've never tried it but if your trip is just a couple off hours away, you would probably be OK if you have concerns about running in propane mode while traveling down the road. Have a great trip!!!