Are you looking for Internal Battery devices or External Battery Devices?
Internal battery devices are all inclusive, meaning that the battery is already in the device, ready to satisfy your vaping desire. These devices are charged via USB cable, which you receive when you buy an internal device, so there is no worries about having to switch out batteries and you can plug in and go!
External battery devices require 18650, 20700, 21700,or 26650 batteries. Most vapes require 1 or 2 18650 batteries to power the device. One of the best things about external battery devices is that once the pair of batteries die inside your device, they can be swapped out with a fully charged pair. If you charge your batteries with a battery charger instead of inside the device, your batteries will last you a long time and keep a full charge with good care.