If you don’t want to go through the hassle of putting batteries in your electronics to test them out, then you’ll want to try this easy trick to help tell whether a battery is still good or bad. I was a little dubious at first so I took some batteries I knew were both good and bad and tested them using this trick to see how accurate it was. I was surprised to see that 85% of the time this trick worked in predicting whether a battery is good or bad. What’s the trick? Check out the video below to see an example:

Curious about the science behind this? Engineer Lee Hite explains why in this video.

So if you’re ever unsure about a bunch of batteries you have in your junk drawer, all you need is a hard surface to test them out! Another strange trick that works is if you ever wonder whether the battery in your remote control is empty just hold down a button your report control and look at the top of your remote through your smartphone camera. If the battery is still working you’ll see a small light that is not perceptible to the human eye but IS perceptible to your smartphone camera. Show your kids this one it’s a hoot and a nice teachable moment.