Check the specs for any unit you are interested in. Good fridges are real efficient. My ARB 50qt is rated for 7amps and Ive never seen it draw that much. Seems to draw around 4 while running. I’ve never drawn my 100 ah Lifepo battery down to even 80% while running the fridge, vent fan, camper lights, charging, etc. I do tend to move every day and I charge from a DCDC via the starting battery, but when stationary its fine with some minor top off with portable solar, which I rarely need.
I could easily be doing fine with just a 50ah battery. As long as you‘re not trying to run all sorts of 120v high draw stuff off an inverter all the time you’ll be fine.
To update this:
Just ran my ARB 50 for 5 days, 4 nites without charging. Here’s the details:
- Battleborn 100 ah battery run down to 36%; shunt said I used 69 ahs
- Temps were low 60s at night to high 70s, maybe 80 daytime
- Fridge is in an ARB insulated cover, and I’ve also lined the cover inside with reflectix. Its in my campser shell, but open to outside air much of the day, but also closed up for hours at a time in the sun. No direct sun on fridge
- open at breakfast, lunch, dinner and happy hour, but we typically aren’t in it all the time for drinks all day
- temp set at 35° with range of 32 to 38 as it cycles, we typically put 2 to 3 warm beers in daily to cool
- shunt shows fridge took 3.8 amps consistently as it runs. Best guess is it ran maybe 15x per day for maybe 5 mins, but wasn’t counting
- also running Maxair fan all night on low (.3 amp), when cooking and other times medium to med-hi (.8 to 1.5 amps) daily
- charging 2 phones, an iPad, 2 Kindles, running a small 12v heating pad for 2 hrs, running a few small draw (< 2 amps) other devices for maybe 2 hrs total
Hope that helps! YMMV …
