Power for a camping weekend

For two days away from mains power, count the energy used by every device over both days. The calculator starts with a cooler, smartphone and LED light. Its estimated values can be changed to match your devices.

The starting example uses 240 Wh for the cooler, 15 Wh for the phone and 24 Wh for lighting: 279 Wh per day. With 90% output efficiency, 90% usable capacity and a 10% planning reserve, two days require about 758 Wh of nominal capacity.

A kettle affects two different numbers. Running at 1,500 W for six minutes uses 150 Wh per day, but still requires the full 1,500 W while switched on. Check energy and power separately.

Solar and car charging are additional scenarios. Expected solar yield is not guaranteed supply. Start with the no-recharging comparison, then consider the charging opportunities actually available.