I picked up a Halloween costume that included a set of glasses with glowing eyes. The hood has a black mesh panel that hides your face but allows the glowing eyes of the glasses to show through. The eyes fade on and off and it is a really nice effect. However the circuit uses three AA batteries housed in a big black box connected to the glasses with a thick black cable. This could be operated off of three button batteries and attached right on the glasses. LR44 batteries would fit nicely and are easily available.
Need something to hold the batteries together. I could have used rubberbands, tape, or various other things. But the Makerspace has 3D printers! I was just about to start designing something when I realized I couldn’t be the first person that wanted a button cell battery holder. A quick search on Thingiverse turned up this Parametric Button Cell Battery Holder which I printed in ABS.
Cleaned up the holes a bit. Batteries in the background.
Wires pushed through the holes and looped around to form the contacts.
Removed the circuit from the huge battery case. Pulled the switch out also. The resistor was just soldered in there, hanging free.
Shortened up the wires, mounted the circuit board and the switch to the arm, and used shrink tubing to cover the solder joints. Everything works great and it was a big improvement over the original setup. The batteries would not stay in the holder so I ended up using some electrical tape to hold them in. If I were to do this again, I would try LR44 battery holder.