Powerful Battery The Nitecore NBP100R 10,000mAh rechargeable Li-ion battery is specifically designed for the Nitecore MH40 Pro flashlight, delivering the equivalent power of two 21700 batteries with its 36Wh capacity. USB-C Charging Fully charged, the NBP100R provides up to 62 hours of runtime and can be recharged in under 4 hours via its USB-C port. A built-in charging indicator flashes red during charging and remains solid when fully charged, making it easy to monitor power status.