I just recently bought my tomtom one 125. I like it and it functions fine. My problem is charging it. I have the car charger and usb cable that came with it. As I understand it I can use both to charge my device. However in the manual it's no specific on charging procedures. Using the usb cable, does my device need to be on or off? If on do I need to accept connecting to my pc? How do I tell if it's charging or not? What does the green light on the bottom of the unit when it's on....just that it's on or being charged?