Bouncing batteries reveal charge level

[OffGridInTheCity]

This was kind of intersting!

 

[Korishan]

Yup. Very quite interesting. Really only can tell between a batch of batteries you may have that are tossed randomly in a drawer. Otherwise opening the package you'd know which ones were charged
I'm not sure if he reposted this video or just did a short clip of a previous one. But I'm pretty sure I've seen him do this video before.