The NL2153 is a size 21700, li-ion, rechargeable battery. With 3.6V/5,300mAh, it is built for high-drain devices. 8A of continuous discharge. Protected against overcharge, overdischarge, short-circuit, and has a pressure relief valve that will activate if high temperature is detected. Recharge via compatible chargers, including UMS2, UMS4, Ci2, and Ci4.