Why power-station runtime differs from the label
Understand conversion losses, duty cycle and startup power.
Rated capacity is stored energy
A station labelled 2,048 Wh will not normally deliver every watt-hour through its AC socket. The inverter and battery management system consume or reserve some energy.
Loads are rarely constant
Refrigerators and pumps cycle. Laptops change power with workload and charging state. Measuring a full day gives a stronger estimate than using maximum rated watts.
Check power as well as runtime
A station may have enough energy but still fail to start a compressor or pump. Compare continuous and surge output with the appliance requirement.