How to disable USB charging of external devices in windows 7
Solution 1:
Nope. The 'charging' isn't a feature of USB, it's just the device using the voltage supplied by the USB port, which the ports are always supplying (sometimes even when the computer is "off").
Unless your system's motherboard BIOS allows you to make adjustments like that to the ports (which I've never seen personally) I think you're out of luck.
Also, depending on the phone itself there may be a way to disable it, but that would depend on the phone. There is a utility written for (some) Android sets that supposedly disabled the charging on the phone called USBChargeCommander, never used it, but it may be worth looking into a bit:
WHAT THE HECK IS THIS?
USB Charge Commander is an application designed for the ZTE Blade/Orange's San Francisco handset.
WHAT DOES IT DO?
It takes care of disabling the charging of the battery, and re-enabling it.
WHY?
Handy if you just want to plug in the handset and copy a file instead of messing up the battery by plugging it in and to unplug it a minute later.
HOW?
There's a simple property set up in the init.rc, that watches for the boolean flag and sets it according.
Solution 2:
Supplying power to an active USB port is required per USB protocol. Your only chance is to disable the USB hub that hosts this port altogether:
- Open Device Manager
- Locate the needed USB hub (you might have several, select "View devices by connection" from the menu to see the tree and not a flat list to quickly locate which hub you need to disable.
- Check the "Allow the computer to turn this device to save power" from the hub's properties.
- Right-click on the hub and select disable from the menu.
Hopefully will disable the hub and cut the power to all connected devices.
Warning: this will disable all devices connected to this hub, you really cannot cut power to just once device. If you have, say, USB mouse, it might get disconnected as well.