The Nitecore Extension Battery Case is compatible with a variety of head torches to provide longer runtime. Ideal for outdoor excursion such as trail running, climbing and hiking, the unit houses 1 x 18650 li-ion battery (not included). It can be used with the following Nitecore headlamps: NU40, NU43 and NU50.

The 18650 case connects directly to the headlamp via USB-C and attaches to the headband with a sturdy plastic mount. When the light is on, power is taken from the extension case first. Simultaneously the battery case charges the headlamp's built-in battery, allowing it to function to its fullest potential.

With a USB-C input and output the extension case can be used as a battery charger or a power bank, making it ideal for charging various electronic devices.

Blue power indicators can be activated to show the remaining battery level:

• 4 lights = <100%
• 3 lights = <75%
• 2 lights = <50%
• 1 light = <25%

In addition, four flashing red lights are available for safety and emergency use.

The Nitecore 18650 Extension Battery Case user manual can be downloaded here.