I had a 50 quart ARB in my possession for a while and tested it. The provided ciggy plug cord was only 16awg. The voltage drop on that cord when the unit was pulling 60 watts, was ~2 volts and was allowing the low voltage shutoff to kick in when the battery was still easily able to power the fridge for another 24 hours.
Here, Danfoss/secop, who makes the compressor used in the ARB, recommend wire sizes for certain lengths, and the cord provided with the ARB is basically criminal when looking at their recommendations.
http://files.danfoss.com/TechnicalInfo/Dila/06/bd35-50f_electronic_unit_ac-dc_04-2009_ei100g402.pdf
They say 10 awg is good for 20 feet, which is total circuit length, meaning + and - wires together, so a 10 foot power cord would need to be 10awg and anything longer 8awg
Danfoss powered fridges are more susceptible to voltage drop on their power cords. The ciggy plugs and receptacles are always an insult to electricity, but combine this with 16 awg power cords to the unit and it is close to criminal.
These fridges work much better and more reliably and more efficient the higher the voltage they are presented with.
Minimal voltage drop should be sought in the power cord from fuse block to Unit itself for best most efficient performance. There is no point in turning battery power into heat, and that is exactly what happens when too thin of copper is combined with ciggy plug receptacles.
12v accessories HAVE to come with ciggy plugs as it is the ubiquitous connector used in every vehicle, but it is an absolute crap electrical connector and will cause issues at some point, and more so and sooner when the device requiring power is capable of 60 or more watts draw.
I used 45 amps anderson powerpoles for all my connectors, but getting 8awg into them is not for the Newb.
I still have 7 ciggy receptacles I wired in before I knew better, and these basically are now never asked to pass more than 15 watts, and the spring loaded tips still get warm passing this tiny amount of current, indicating resistance and just an extremely poorly designed electrical connector.
If you want reliability and maximum efficiency, cut off the ciggy plug and feed the fridge from a fuse block with 10awg or thicker. Danfoss says to wire directly to battery and fuse at battery and to not share common busses with other devices.
http://www.genuinedealz.com/8-2-awg...nned-copper-boat-cable-flat-blk-red-by-the-ft