When we go camping for extended periods of time I have a 3way dometic portable fridge/cooler that we run off propane.
It'll run ~2days on 1# green bottle. But we run it on a 20# bottle from a lamp tree.

They're not cheap, but they are handy when the power goes out as well.
http://www.google.com/search?q=dometic+portable+propane+cooler+site%3Acraigslist.org

mine is like this unit specifically (I had picked it up off Craigslist)
http://annapolis.craigslist.org/app/3223129526.html

http://compare.ebay.com/like/190717505573

you may be able to locate one locally thru a large RV supply outfitter,
 but most don't carry it because of the limited audience and sales pricetag.

My brother uses a smaller Dometic 12v fridge that fits between the seats and runs very efficiently, but you'll still need an Aux battery for it.
It'll run 2~3days alone on a 12v deepcycle

From:    Rocket J Squirrel <camping.elliott@GMAIL.COM<mailto:camping.elliott@GMAIL.COM>>
Subject: Re: Fridge Burner box

When Mrs Squirrel come a-campin' we have to bring a separate cooler for her produce and veggies. Me, alone, the Vitrifrigo in the van is sufficient.

What I'd like to find is a small, standalone propane refrigerator that will operate off those small 1-lb disposable propane bottles. Something as movable as a cooler, so we can set it outside when in camp.

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