Have you seen this? I don't think it will work.
https://discussions.apple.com/thread/2537899?start=15&tstart=0
Specifically these lines:
3rd post down by: Michael Fryd
Current iDevices no longer have the circuitry to charge or communicate off the FW pins.
When you plug your iDevice into a FW style charger you will not hurt your iDevice. The higher FW voltage is on connector pins that are not connected inside your iPad.