[Jay Kickliter] built his own coin cell battery recharger. This won’t work on the vast majority of coin cells as they are manufactured as disposable parts. But there are rechargeable options out ...

The ring itself is in two parts: a base, and a cover to diffuse and protect the LEDs. A pair of wires run out from the ring and connect to a printed coin cell holder.

LIKE BOING BOING BUT NOT THE ADS? CLICK HERE TO GO AD-FREE! Yesterday a redditor named joshcam posted a photo of a coin cell battery with purple colored dots arranged in three concentric semicircles.