I bought this one with 18L capacity. They make one smaller size and two bigger sizes. Can run off a Lithium battery in addition to 12V DC and 110V AC. It's very quiet and seems to be pretty good in cooling temps down and maintaining it. It was
@mrblaine idea to look for a fridge that's battery powered and it was an excellent suggestion.
I bought two batteries with it. The idea is to be able to charge the batteries at home, take them on a day trip and even if I forget to charge, I can still so in the vehicle since they just charge with It USB power and Blaine put a dedicated Is USB power supply in the back.
Last year, the fridge+1 battery was 300 and I got one extra battery for 150. The unit can be used at home normally with 110V power. Each battery is 170Wh and supposed to last a whole day with fridge running at 32F, so I'm nicely set up for 1-2 day outdoor trips which is most of what I generally do.
You can see pics if the fridge in my build thread. Blaine made a really awesome mount for it.