Fenix 18650 USB Rechargeable Battery, 3400mAh – F FX-ARBL183400U

The ARB-L18-3400U is a high-capacity 18650 Li-ion USB rechargeable battery with a protection circuit in the anode to help prevent short circuits, overcharge/discharge, and overheating. This battery has its own micro-USB charging port for quick/easy charging without the need for a separate charger. The battery also Includes pressure relief vents that expel waste gas in the rare case of an internal short circuit preventing an explosion.