Interesting. Can you go 24hours without starting the vehicle? I killed my Interstate battery recently by listening to my radio with the engine off for an hour so I think I am due for a replacement. I think I am going to buy some type of power pack either way to carry when I have the fridge hooked up. The Interstate is a third of the price but I want to be sure I can go 24 hours without any issues.
We use our fridge equipped LX470 is used for travel to Mexico as we are leaving in an hour. I does sit overnight frequently (~12hrs) without issue. With that said I have never gone 24hrs. A lot variabilities goes into battery demand when running a fridge. How full, what is in the fridge, outside temp, inside the vehicle temp, ventilation, and the set temp on the fridge. With that said YMMV and I also carry and recommend a jump box for safety.