It seems I can't find suitable information nor parts suppliers regarding the conversion of a normal domestic refrigerator to one that uses Propane.

I have a customer who wants me to convert any given refrigerator (specifically an 18-22 cubic refrigerator) to Propane for campsite use.

I need information on how to do the conversion please.

What cap tube size, suggestions on safety valves, where to get fittings to adapt from the standard propane tank (US-20pound) for use on the refrigerator, etc., and estimated fuel usage per day/week/month.

I don't want to convert the refrigerator to R717 (ammonia) or use any kind of funky adsorbtion system.

How to get the cold control to operate a valve, the fan to work, etc without using anything more than a small square 6 volt battery or two like the kind you use in large flashlights?

The customer can manually defrost the refrigerator.

I supose a small static invertor could be used to drive the lightbulb and fan. But the electrically operated valve for the propane is the question........