watt hour
/ˈwɑt ˌaʊər/
noun
- A unit of electrical energy equal to the power of one watt used for one hour.
- The electric company charges for each kilowatt-hour, which is 1,000 watt-hours.
- A small LED bulb uses only 10 watt-hours if left on for an hour.
- My laptop battery holds about 50 watt-hours of energy.