Your fridge doesn't pull what the box says

A compressor fridge is the most important load in most off-grid rigs — and the most commonly mis-sized.

The spec sheet lies by omission. A fridge rated "50W" doesn't pull 50W all day. It cycles: compressor runs, hits temperature, shuts off, waits, runs again. What matters is the fraction of time it's actually running.

What drives duty cycle: - Ambient temperature — the single biggest factor. A fridge in a hot rig works vastly harder. - Insulation quality — cheap boxes cycle more. This is what you're paying for in the good brands. - How often you open it — cold air falls out of front-opening doors; chest designs keep it in. - Set temperature — every degree colder costs energy.

Moves that cut the number: shade the rig and ventilate the compressor area, keep it full (thermal mass holds temperature between cycles), pre-chill items before loading, don't set it colder than you need.