New answers tagged power-management
That's not possible. Also, modifying a USB cable (as suggested in another answer) is a) probably not a good idea and b) probably won't even work (see this question & answer). Energy-wise, you are most likely better of by just using wifi for tethering.
Not possible, you would have to physically alter the USB cord and remove the pins related to power and leave the data ones intact.
Top 50 recent answers are included