Lithium ion polymer (also known as 'lipo' or 'lipoly') batteries are thin, light and powerful. The output ranges from 4.2V when completely charged to 3.7V. Lithium Ion Polymer Battery - 3.7v 500mAh has a capacity of 500mAh for a total of about 1.9 Wh.
Lithium Ion Polymer Battery - 3.7v 500mAh comes pre-attached with a genuine 2-pin JST-PH connector as shown and include the necessary protection circuitry. Since the JST connector is genuine, the cable won’t snag or get stuck in a matching JST jack, they click in and out smoothly.
The included protection circuitry keeps the battery voltage from going too high (over-charging) or low (over-use) which means that the battery will cut-out when completely dead at 3.0V. It will also protect against output shorts. However, even with this protection it is very important that you only use a LiIon/LiPoly constant-voltage/constant-current charger to recharge them and at a rate of 150mA or less. We suggest Adafruit Micro Lipo - USB LiIon/LiPoly Charger - v1, which has a 100mA default rate.
Additional Safety Notes: Do not use a NiMH/NiCad/lead-acid charger! Also, do not abuse these batteries, do not short, bend, crush or puncture. As with all Lithium ion polymer batteries and with any power source - they should be used by experts who are comfortable working with power supplies.