The fenix arb-l18-2600u battery is micro usb as well as ready to charge within a charger.Led to indicate if battery is done charging.Protection circuit built in the anode with a steel hat by riveting process.Steel shell eliminates the risk of short circuit caused by collision and impact.Pressure relief vent: expels waste gas generated by internal short circuit.Expelling waste gas prevents a cell from inflating or exploding.Three sets of over-heat protection: over charge protection, over discharge protection, short circuit protection, and overheating protection.500 charge cycles: a properly maintained arbl18 battery is designed to retain up to 75% of its original capacity at 500 full charge and discharge cycles.*note- does not include usb charging cable.

Rechargeable: Yes
Nominal Voltage: 3.6v
Rated Capacity Mah: 2600