Summary

First, a caveat—do not give these to kids. Button batteries seem harmless, but they’re actually really dangerous. When swallowed, they lodge in the esophagus and cause horrible corrosion and perforation. Bad stuff. Trust me on this one.

Most folks may have heard of LED Throwies—a disc battery, one LED, some tape and a magnet create a glowing light that can be tossed onto a high metal sign or post and will glow for days to weeks. I decided to make a 3D printed skull version of one. You don’t need much: the 3D print, a 10mm LED, and a CR2032 battery. You might need some tape or hot glue, but often sticks in without either.