How many AA batteries does it take to use a heating pad for an hour?
About 22 AA batteriesA heating pad draws about 65 W, and one AA holds about 3 Wh.
It takes about 22 AA batteries.
How we worked it out
A heating pad draws about 65 W, and one AA holds about 3 Wh. Alkaline AA batteries, about 3 Wh each, and no energy lost on the way. Real life adds a little friction and waste, so treat the number as a solid ballpark rather than a lab result. The constants behind every experiment are on the science page.
Watch it happen
This was one of the five experiments in It Took #21. In the game you guess first, then the experiment plays out with your number: too few and it fails, too many and it overshoots.
Play It Took #21Play today’s experiments
More aa batteries questions
- How many AA batteries does it take to make one cup of tea? About 8.
- How many AA batteries does it take to toast a slice of bread? About 11.
- How many AA batteries does it take to leave a Mac mini on overnight? About 11.
- How many AA batteries does it take to charge a Steam Deck? About 17.
- How many AA batteries does it take to fully charge a laptop? About 22.
- How many AA batteries does it take to microwave a meal for 5 minutes? About 28.
- How many AA batteries does it take to boil a liter of water? About 31.
- How many AA batteries does it take to dry your hair for 10 minutes? About 56.