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. This battery has a capacity of 2400mAh for a total of about 9 Wh. If you need a smaller battery, we also have a 1200mAh modelThe batteries come pre-attached with a genuine 2-pin JST-PH connector as shown and include the necessary protection circuitry. Because they have a genuine JST connector, not a knock-off, the cable wont 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 ~2.8V. 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 1200mA or less.Like most lipos, the batteries we