Fenix ARB-L14-1600U Built-In USB Rechargeable Battery

ARB-L14-1600U is a high capacity 14500 Li-ion rechargeable battery with a built-in micro-USB charging port.  It also includes a protection circuit in the anode to help prevent short circuits, over charge/discharge and over heating. This battery can quickly be charged without the need for a separate charger.  This not only save you money from purchasing a charger, but also convenience of not having to carry around another device.  This will work in all of the models that utilize the standard AA battery. This battery is a great rechargeable alternative to alkaline AA battery.