These are very slim, extremely light weight batteries 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 850mAh! 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 LiPo charger.
Battery includes built-in protection against over voltage, over current, and minimum voltage.
Note: Although these cells are rated for 2C continuous discharge, the wiring and connectors are only rated up to 1A, so be sure to take that into account when determining your power requirements.
Note: Be careful with the JST connectors. They can stick in pretty good and tugging on them can damage the connector. Check this tutorial for an easy way to remove them safely.