@TechConnectify Thanks for the great video! As always, it’s a fantastic introduction to a fun technical topic. I’ve never seen these batteries, but my grandfather gave me a multimeter when I was a child so I could test whether the batteries were still charged.

P.S. For those like me who prefer not to visit Google sites in the same browser they're logged in to, here's an article about battery power meters that's cited in the video: tedium.co/2021/01/20/on-batter