The Nitecore NL1834R Li-ion battery offers heavy-duty power for LED flashlights and other high-output devices. This battery requires no external charger, and can instead be connected directly to a power source via standard Micro USB cord. The battery provides 3.6 Volts, and a 3400mAh capacity for long run times on the go. Charging cable not included. Features: Built-in Micro USB charging port for easy charging without carrying bulky chargers. Compatible with external charging devices if desired. Designed for high-power drain devices: flashlights, lanterns, headlamps, and other devices.