The eGo-C 2 upgrade battery is the newest improvement of Joyetech battery. It comes with the logo "eGo-C TM upgrade" branded laser in the bottom steel plate and "CE" and the WEEE label in the connector part. Each Joye eGo-C 2 upgrade USB battery or Joye eGo-C USB passthrough has a built-in 1000mAh eGo-C battery and a USB port, which allows the user to vape during charging. A fully charged Joye eGo-C 1000mAh USB battery or Joye eGo-C USB passthrough can support a heavy user to vape at least 10 hours! It's sealed to protect from e-juice or e-liquid. Take it as a spare. There is a manual inside to instruct you how to use it! It can work with Joye eGo-C/eGo-T/eGo/510/510-T atomizers!