I understand it with a 500mA charger why the navigation would drain the battery while plugged in for the Rezound. However, I've managed to prove beyond a doubt that the internal charging capacity of the rezound is not sufficient, and cannot support GPS, display and 4G. I shorted pins 2 and 3 on the USB A side of the connector to ensure the "on AC" signal was present and that the phone would charge at the > 500mA rate. The vehicle charger I used for the test was a Rocketfish RF-M657D, rated at 3 amps. At no time did the phone pull enough current to increase the battery level. This is without question a critical flaw. Why should I have to tinker with phone settings for this. This, plus no real hope of root means bye bye Rezound unless I hear something soon.