Adler Barbours are designed to run off 12V...they typically use 5-6 amps when running but once the box is cooled, they only run about 1/2 the time in temperate climates. So YES you can run them off of batteries. I would figure 100 amp/hours the first day of use since you have to cool down the fridge and then about 60 amp/hours for each additional day.
The next thing to worry about is DO I HAVE A BIG ENOUGH battery bank?
Aside from your starting battery you will need about 300 A/h's of batteries to run the fridge for a weekend since you should only use 1/2 available amps before you recharge your batteries. This is equal to about 3 group 31 batteries or 2 4D types.
Then...you need to figure how you are going to charge those batteries since you will need to replace 160 amp/hours every 2 days. You'll need a marine
battery charger and a generator (like a Honda) OR some combination of solar/wind generation to achieve this OR you will need a decent sized (80 amp or so) alternator on your diesel and a smart 3 stage regulator...not recommended due to the engine wear running at Idle causes...but still used by many.
Hope that helps...as you can see...it is a bit more complicated than just hooking up a battery...but the ice cubes are worth it!!