Fenix 5000mAh 21700 USB-C Rechargeable Battery The Fenix 21700 rechargeable battery combines a 5000mAh rated capacity with a 3.6V voltage specification. Its USB-C charging port is built into the battery, providing a direct charging connection. The 21700 format identifies the battery size class to match to a compatible device, while the capacity states its charge-storage rating. The rechargeable design allows the cell to be charged again for repeated use in a compatible device. USB-C specifies the charging connector type. Battery size and voltage remain separate from capacity, so all three specifications matter when selecting the correct cell. The black appearance identifies the stated configuration. Key Features Rated capacity: 5000mAh charge-storage specification. USB-C port: Built-in charging connector. Rechargeable format: 21700 size-class battery. Voltage: 3.6V specification for compatible devices. Specifications Manufacturer: Fenix Size class: 21700 Capacity: 5000mAh Voltage: 3.6V Charging port: USB-C Color: Black Shop the Fenix 5000mAh 21700 USB-C Rechargeable Battery at BattleHawk Armory.