Yesterday a redditor named joshcam posted a photo of a coin cell battery with purple colored ... concentrically around a little bit more than half of the circumference of the battery.

This is obviously far in excess of what a coin cell can put out instantaneously ... He notes the current charge efficiency is around half of what’s needed according to his calculations, but ...

Rechargeable coin cell batteries are great for all your small projects. They look exactly like regular coin-cell batteries, but in a shocking turn of events you can recharge these little guys.