Fenix ARB-L18-3500U Built-in USB Rechargeable Battery 3.6V

ARB-L18-3500U is a high-capacity 18650 Li-ion USB rechargeable battery with a built-in micro-USB charging port.åÊ It also includes a protection circuit in the anode to help prevent short circuits, over charge/discharge and over-heating. These USB rechargeable batteries can quickly be charged without the need for a separate charger. This not only saves you the expense of purchasing a charger, but also saves the inconvenience of having to carry another device.  This will work in all of the current models that utilize a li-ion 18650 battery, including best sellers like the PD35 V2.0, PD35TAC, TK20R, TK75, TK15UE, and more. A micro-USB charging cord is NOT included.