Some mobile phones will not charge their batteries from the USB port of you don't have special software installed on the PC to activate that function. The moti

Some mobile phones will not charge their batteries from the USB port of you don't have special software installed on the PC to activate that function. The motivation is that you might not want to charge from USB all the time, especially if your notebook is currently running on batteries, too. Of course it's much more practical to have a corresponding switch on the plugged in device, instead of having it in the PCs driver.