This guy came up with a simple trick to test how to see if the battery is dead or still working. There is of course a testing device you can buy for testing batteries. But this cool trick will come in handy in situations where you cannot find a testing device. He drops them from from couple of inches, and the working battery stands up right, while the dead battery bounces and tips over. Check the video to see the trick:

Source: Amazingly simple way to test if a battery is dead by Socialentertainment on Rumble