The external battery is used to produce energy for vape device. There are many types of batteries such as 18650 battery, 20700 battery, 21700 battery, 26650 battery for your selection. With high quality and multiple protection, the power battery will bring you a strong and safe vaping experience. The smart battery charger are also available. With the battery charger, you can charge the battery easily and safely. Before placing order, please make sure you know the common sense about the battery safe.