The new Nitecore NL1826R 18650 battery is a revolutionary battery designed with a built-in USB-C charging port making charging easier than ever! No more need for an extra charger as this battery can be charged directly using a standard USB-C charging cable (sold separately). Simply plug the battery into an available power source, and a red indicator light under the + pole (positive) will turn green upon completion. Alternatively, these batteries can still be charged on an external charger if desired. The NL1826R batteries are designed for powering high-drain devices such as high-output flashlights, lanterns, headlamps, and bike lights, as well as a variety of other appliances and devices. With built-in smart charging circuitry and other integrated safety features throughout, this battery will safely work in the majority of button-top compatible devices.