The Nitecore HLB1500 1500mAh rechargeable Li-ion battery pack is designed specifically for the Nitecore UT27 and HA13 headlamps and the Bubble Lantern. At 5.78Wh, this small cartridge provides 20% more capacity than the previous generation and a longer runtime of up to 14.5 hours. The Nitecore HLB1500 Li-ion Battery pack is 3.85V and can be fully recharged within 1 hour and 30 minutes via its USB-C port. Red and green indicator lights are built into the battery for a real-time charge status.