This tiny coin cell battery holder is ideal for small portable or wearable projects. It holds one 20mm coin cell (also known as CR2032) in series to generate 3V nominal. 20mm coin cells are popular as they are used in keychain lights and remotes, so they are easy to get and fairly low cost. They tend to have about 220mAh capacity.
The holder is made of plastic and snaps open and closed with two tiny screws. There is a 13cm-long plain wire on the end, for easy attachment or soldering to whatever circuitry you wish to power.
We also have a version with 2 battery slots for a nominal 6V