The Nitecore NL2150HPR is a high drain 21700 lithium-ion battery designed for high-output lights. With 3.6 volts of power and a 5000mAh capacity, this 21700 is ideal if you want a high-powered performance. Easily recharge via the built-in USB-C charging port, plus there's a charging indicator that glows red during charging and green when fully charged. Nitecore has pulled zero stops when it comes to internal safety features for this battery. With built-in PTC to prevent current surges and pressure relief valves that prevent rapid temperature increases, you can rest assured this battery will keep your devices working in peak condition.