I shop so often that I've been able to do without a fridge, but it's a
bit inconvenient. Recently, I was given one of those 'cool box' mini
fridges, a 10-litre job that can run on either mains or 12v battery,
but I'm wondering if it's a false economy in terms of power
consumption.

I've found that, unlike a 'proper' fridge, it doesn't have a
thermostat, so it's working all the time. I tried using it without
anything else switched on, and found it uses more than two untits a
day - that's about 35p per day.

I don't know anything about full-size fridges, so could someone tell
me if a small 'proper' fridge would go through less electricity?
Thanks.