If anyone is wondering why their Optimus V is charging slow I found out why. The OEM charger outputs 5.1V while the USB connected from the computer is only 5.0V. When the phone sees 5.1V is goes into "AC Power" charging mode. You will notice it charges a lot faster and the battery will get warm. Download the app OSMonitor and select the Misc tab. You will see what mode your phone is charging; AC Power or USB Power.