How Do You Convert Watts into Kilowatt Hours?

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To convert watts into kilowatt hours, first divide the wattage by 1000 to obtain kilowatts. For a device running at 72 watts, this equates to 0.072 kilowatts. Multiply this by the number of hours the device operates to find the total kilowatt hours consumed. For example, if the 72-watt device runs for 3 hours, it uses 0.216 kilowatt hours of energy. Understanding this conversion is essential for comparing energy usage, such as that from a typical car battery.
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Let's say, for example, that I have a common household item that is 6amps, being run from a 12v circuit, like a car battery. That would make the wattage 72, correct? What is the time frame on that? Is that 72 watts an hour? a minute? Basically, how do I convert that number, 72watts, into a kilowatt hour? I'd like to know basically, how many kwh come from the typical car battery, in a comparison for class.

Thanks!
 
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Watts is a rate, it's 72 watts now and it will be 72 watts 3 hours from now (as long as it's still running).

Kilowatt hour is a unit of energy. Just turn watts into kilowatts by dividing wattage by 1000, then multiply by the hours the thing is running to get kilowatt hours.

If a device is 72 watts and it runs for 3 hours, 0.216 kilowatt hours of power is used.
 
Make that 0.216 kW-hr of energy.

- Warren
 
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