Question: how long is 1 watt hour?
Answer: The watt-hour (symbolized Wh) is a unit of energy equivalent to one watt (1 W) of power expended for one hour (1 h) of time. The watt-hour is not a standard unit in any formal system, but it is commonly used in electrical applications. An energy expenditure of 1 Wh represents 3600 joules (3.600 x 103 J).