[hooover]

Yes it is safe to charge your phone via usb, not really sure if there is a way to change it to be exclusively usb kinda sounds pointless seeing how its done automatically.As mentioned previously the usb charge from your pc is 1/2 the amount as the wall charger, that is why i feel like I get a more crisp charge from my pc then the wall but that's just a matter of personal opinion and has been discussed on threads before. Personal now i only use usb when I'm to lazy to walk upstairs and get my phone charger or if I have been drinking and I'm about to pass out on the couch, lol...