I am installing an iPad mini in my car a touch screen interface. The backend is ford sync. Everything is working pretty well so far. The only problem is the power limitation of the usb port. I was thinking about getting the lightning to 30 pin adapter and modifying a 30 pin cable. I see that a pin out diagram shows 2 12v+ pins but they are labeled for FireWire. If I wired a switched 12v+ cable from the car to the those pins would that provide enough power to charge?

Thanks for any help. I'll try to draw a diagram of what I'm trying to say.