[Paul Niedermeyer]

That is actually very good efficiency. With numbers like that, it is tempting to just use a good full size refrigerator. I have wondered how much of the Energy Star rating is from actual refrigeration vs defrost cycles. So you are using just 250 amp -hrs @ 12 volts of battery pack and 300 ish watts? Is this in an area with fairly clear sky?

These units do not defrost, which undoubtedly contributes to their efficiency. This unit's Energy Start rating was 221 kWh/year. And I see the price has gone up on these quite dramatically: I paid $129; they're now around $200. My battery pack is 220 AH (2x 6v golf cart batteries). Presumably, yes, on the 300-ish watts, based on the three days I plugged it into the Kill-a-watt. That's at the fridge 110 outlet, so there's some further loss at the inverter. This is Oregon, but yes, in the summer-fall, we generally have lots of sun.

 

[dog_house]

If you have sunk big money in an inverter that you plan on running all the time anyway, there is little advantage in a 12v fridge. That's not most people and the standby draw will by far exceed what the fridge uses.

I used a dorm fridge in my work truck that ran all week for years on an inverter and single group 31 battery with alternator charging. The battery would not make it over the weekend, in fact it would not even run the inverter two days with no load at all.

I put the money into our electrical system and not a $1200 fridge since the inverter standby was a sunk cost power wise, we are running it 24/7 for other reasons. The inverter uses around 1.2kWh to run a compact fridge/freezer if it's cooled down and not opened. This is going to be a higher in a hot van. The kicker is 700wh of that is the inverter standby so the fridge is only using around 500wh (about 40ah @ 12v) which is right in line with what the 12v units draw.

 

[skibuoy1959]

Feels to me like you're getting lost in the numbers. Bottom line is most dorm frigs are junk. Get a higher end RV frig that runs on 12v and 110 and you'll be way happier. Ive got one with a big freezer and it's awesome. Pulled out the dorm frig the prior owner had....never looked back. Similar to this one
refrigerator-with-freezer-compartment-vitrifrigo-c115ixd4x-1?gclid=Cj0KCQjwwtWgBhDhARIsAEMcxeDRJRmX09fWoeLW5hjkXdEhaJC5-4qdiJjDlgcs2oayxA-RfUzcDtgaAlceEALw_wcB