I am trying to run a dorm/mini fridge on a homebrew solar power system for long term camping (not an RV). I have purchased a 100 watt solar panel which charges 2 35ah batteries run in parallel. The fridge I am trying to run uses 1.5 amps at 115V, the compressor duty cycle is approximately 82% running for every 18% off. Originally I had thought my batteries would be large enough, But after testing it the result is that every time I try to run the batteries for any considerable time, they go dead if the panel is not in full light (very annoying at night or on cloudy days). My main questions are: Is there an exact equation that will tell me how many 12volt DC amps I need for every 120volt amp AC? What should my total ah required amount to after I account for running without sun? Once above is determined, how much solar wattage should I use to keep those batteries charged?