Nigel replied:

The Unisolar panels are probably the best choice for mobile use as they don't have any glass and cope with heat and/or shade better. A 64 watt panel will put in about 4 watts in full sunlight. So if your fridge averages 2 amps then you need 48 amps a day. If you can get 6 hours of good sunlight a day then 1 panel will put in 24 amps a day. So 2 panels (in theory) would keep you going indefinately, except that battery's need more input than they will put back out, so your battery may be flat after a couple of weeks, but thats a lot better than only getting a couple of days. So you'd need 3 panels to be self sufficient, but even a single panel will extend your battery usage time by 40%. Be wary of other brands of panel as they only put out their rated current when the temp is at or below 25 degrees and partial shade reduces their output to zero.

Andrew Donald replied:

I'm not experienced in these matters, but do you need to face the panels towards the sun to get full rated output from them.

Fred replied:

John I'd strongly recommend you buy a second fridge - pick up a second hand 3way Finch for about$100. A 3kg gas bottle will go for about 12 days. Gas is the only reliable way to go for camping without running the vehicle.
Good Luck!!

Rob G replied:

hi john,

i did a quick round oz in nov/dec last year & had a single unisolar 32W panel on the roof. it managed to give me 2-3 days on my 39l engel. an additional panel would definitely be the go for me next time. mind you, my engel is 10 years old & takes a bit of cranking up for it to start humming along.