Thinking about a Truck Fridge.

I have a NovaKool which I believe has a capacity of a little over 4 cuft. These and most other 12 v compressor fridges or freezers use the German built Danfoss compressors. The Engels uses a Japanese equivalent. With the Danfoss, the manufacturers can select the compressor size and they can alter the power consumption and output needed for the specific model. Most of the smaller units will run at about 2.5 amps @ 12 volts. On cool days most units are set to run about 30% of the time. Since the small units have a freezer compartment within the main unit, it is necessary for the unit to run frequently to keep the frozen food actually frozen. On a hot day the run time and power consumption increases rapidly and @ 90 oF the unit is likely to run constantly. That would result in power consumption of about 60 AH per day. Opening and closing the unit and adding warm beer to be cooled will also have a large effect on the efficiency. Plan on a couple of high capacity RV batteries and at least two solar panels in the 100 watt range.

Note also that the proper installation is essential. The fridge will not run efficiently unless there is a lot of air flow around the compressor. The wiring is also very important. My fridge is on the opposite side of the camper in relation to the batteries. I needed close to 40' of wiring to reach the fridge and return to the battery bank. The dealer had installed 10 gauge wiring. The voltage drop and losses due to resistance were huge. I needed to go to 6 gauge wiring.