Some measure cooler performance in days… here at Engel we measure it in decades. With Engel AC/DC powered fridges you’ll never need to buy ice again, they run on the car’s 12v battery and auto-switch to 110v*. They have the world’s best compressor, the Sawafuji Swing Compressor, which allows for temperatures as low as 0 degrees Fahrenheit and up to 90 degrees below ambient with very low amperage draw and low power requirements. *compatible units.