No, Backbone One does not have a battery! Backbone One draws minimal amounts of power from the phone. Its power consumption is imperceptibly low. The degree of Backbone One’s power consumption is so trivial that you could leave Backbone One plugged into your phone overnight without any discernible change in your phone's battery life.
That being said, games running on your phone can consume considerable amounts of power due to things like graphics, networking, and audio. Therefore, recognizing that battery life is critical to gaming on mobile devices, we’ve designed a pass-through charging port on the Backbone One to allow for charging your phone while playing.