This is an extremely tiny and light weight battery based on the new Polymer Lithium Ion chemistry. This is the highest energy density currently in production. Each cells outputs a nominal 3.7V at 40mAh. This may sound like not so much power, but the cell is really tiny… like, about half an inch square!

Comes terminated with a standard 2-pin JST-PH connector - 2mm spacing between pins. These batteries require special charging. Do not attempt to charge these with anything but a specialized Lithium Polymer charger. Battery includes built-in protection against over voltage, over current, and minimum voltage. Please use caution when using this battery in wearable projects. When using conductive thread, a short in the thread can create sparks and heat. We recommend using coin cell batteries for beginners.

QUICK SPECS:

• Rated Capacity: 40mAh
  
• Nominal Voltage 3.70V

• Datasheet
  
• MSDS