The new ARB fridge has an under-voltage protection circuit. That is, it monitors the available voltage and will shut itself off if it gets too low. There are 3 settings as shown below. Our old battery was totally shot. If we parked the Jeep without the fridge in it for any more than 24 hours it wouldn’t start. We went with this Odyssey PCM-1500M, which features a reserve capacity of 135 minutes. We set our battery monitor at Medium because our TJ sometimes has problems starting under 10.5 volts. The fridge draws only 0.95 Amps/hr so we can get about 21⁄2 days in 80 degree weather before the Battery Monitor shuts it down.