I'm running a New iPad, a Bad Elf GPS unit, and Navigon car navigation software. I'm powering this set up using a Kensington PowerBolt Duo.
In this configuration, the iPad indicates it's charging, but I can watch the battery percentage slowly decreasing during long drives. It seems to me this should not be happening. I know the New iPad draws a lot of power, and when you add in the Bad Elf and the navigation software it's drawing heavily, but I would expect that at least the battery level would be static, if not adding charge.
I have tried three different 12v chargers and the iPad loses battery charge with all three. I'm out of ideas. Any suggestions? A 12v USB charger rated for 2.1 amps and 5 volts output ought to be sufficient.