Originally Posted by vostok4
I already tried something like this: putting 5V on the power pins when the shield was in OTG mode. Didn't work, the SHIELD didn't recognize the charge in software.
Another idea I have for this would not allow charging but it would slow down the rate of battery drain.
I doubt you would find this cable premade, but instead of applying power to the usb otg circuit it would only connect the 2 data wires to the shield, and the 2 power wires to the wall charger. That should allow your usb device to be powered by the wall charger and no the shield allowing the battery to last longer.
Yet another possibility is to add a diode in to circuit to only allow power to flow into the shield on the 5v+ line.
Current Devices = Galaxy S3
Previous Devices = Galaxy Nexus (Sold) <- Xperia Play R800x (Lost) <- HTC Rezound (BRICKED) <- Motorola Droid
Previous Tablets = Nexus 7 (16GB T3)
Useless Devices = NVIDIA Shield