The Nitecore Extension Battery Case is designed to extend the battery runtime of the NU40, NU43, and NU50 headlamps. When the headlamp is on, it will first be powered by the battery case, followed by the built-in battery of the headlamp allowing it to maximize its runtime.
Weighing only 2.2 ounces and directly attached to the headlamp band on the back, it provides a balanced weight distribution to the user for a comfortable and secure wearing experience.
The Extension Battery Case is compatible with high-capacity 18650 rechargeable batteries, excluding flat-top batteries. Equipped with an intelligent charging function, connect a USB cable to a USB-C adapter to begin charging the battery when not in use. For added safety, it features four red flashing lights to act as a signal light at night. Short press the Power Button for the power indicators to illuminate your remaining battery power.