Today I used iPhone 3GS plugged in Griffin SmartScan charger/FM. And I run iPod playing music, and Google Map tracking location using GPS, using either 3G or EDGE. My battery drains even if it is plugged in. Slowly. After about one to two hours, it about 70% battery left (start with 100%). However if I leave Google map and only plays music, the battery will be charged, i.e. the percentage will increase. Once I turn on Google Map + Tracking, it drains the battery even plugged in. Is this common problem for everyone? Or could it be my car is not providing enough power? Thanks!