Watts: the rate of using energy
A constant 100W load uses energy at a rate of 100 watts. Your power station’s rated output must cover the devices you run together. Motors can need additional starting power, which requires its own check.
Watt-hours: the amount of energy
Running that 100W load for three hours uses 300Wh. A battery’s advertised Wh rating is nominal stored energy. The usable energy delivered to an appliance is lower once conversion losses, overhead and reserve are considered.
A useful example
With a 1024Wh battery, a constant 100W load and our default planning assumptions, estimated runtime is about 6.9 hours. This is a model, not a measured runtime: 1024 × 0.85 ÷ (100 ÷ 0.85 + 8).
Read the right output number
Compare the rated continuous AC output first. Then check starting demand. Special boost or power-lifting modes should not be substituted for a verified starting rating when selecting a battery for a motor or sensitive equipment.
Sources & context
Virginia Cooperative Extension — appliance energy calculations ↗Research checked October 22, 2026. Calculations and example loads are illustrative. Product-specific advice should be checked against the relevant manufacturer documentation.