Battery low after camping

+2 to SH, have always run fridge on propane while traveling.  My dad did the same with a fridge he added to a popup he had in the early 1960's as well as with the built-in on his 1968 Shasta travel trailer.  No issues with propane, nor have I ever read of or known of anyone who has ever had a safety issue while running their fridge on propane while traveling.

+1 to Mike. Charging with propane is always safe; until it isn't. Problem is, you may not get a do over if something goes wrong.

Problem is running the fridge on battery while towing. It draws about 12A to run off of battery. Most vehicles will not provide that much to a trailer via the 7 pin connector. Whatever it does push, the difference is drawn from the battery. 

Towing with the fridge on LP is risky because you usually have to put gas in your vehicle, and running the fridge on LP means "fire". Fire close to a gas pump is not a good idea. I'm not sure anyone's ever been blown up by doing this, but it isn't something we should risk. 

Get your fridge cold in advance. Pack it with NON PERISHABLE things like water bottles or such. Put some frozen water bottles in when it's cold. It should stay cold enough for a good amount of time. 

I can understand the people that don't have a choice of using battery, or propane, choosing to travel with propane. I've done it once or twice when i forgot to switch over before getting on the road. But IF you have a choice, and you don't use battery, I would call that a poor choice. Most safety rules don't come about because something bad happens every time you do something. They come about because of the one in a million times something bad happens. Osha demands that safety glasses be worn to do some of the most ridiculous tasks. I worked in machine shops with flying chips everyday and never used to wear them. Did I get hurt? Nope. Was it a very good choice? Nope. I now know better, and I never enter a shop without them. I see people who advocate not using a sway bar all the time. What possible reason can anyone say you should "NOT" use a sway bar of some type.