In my car a Nexus 7 is installed as a multimedia system which is connected by Einy USB OTG cable to both power and data. But as I 2 separate power connections needed (cigarette lighter while driving as the main source, radio as a trigger for simultaneous turning on the Tablets) I simply ordered this cable and connected to the free data connection of the Y cable. Behold, now the data connection also acts as a second power supply. Top.