I have a Lenovo laptop that has one "always powered" usb port. My understanding is that ports of this type are color coded yellow. This allows you to charge portable devices without having to keep the computer awake. For me, as long as the hard disk isn't spinning I wouldn't worry about unplugging it.

From http://en.wikipedia.org/wiki/USB_port:

Sleep-and-charge USB ports can be used to charge electronic devices even when the computer is switched off. Normally, when a computer is powered off, the USB ports are powered down. This prevents phones and other devices from being able to charge unless the computer is powered on. Sleep-and-charge USB ports remain powered even when the computer is off. On laptops, charging devices from the USB port when it is not being powered from AC drains the laptop battery faster; most laptops have a facility to stop charging if their own battery charge level gets too low.[74] Desktop machines need to remain plugged into AC power for Sleep-and-charge to work.[75]

These ports are found colored differently (mostly red and yellow). On Dell laptops, the port is marked with the standard USB symbol with an added lightning bolt icon on the right side. Dell calls this feature "PowerShare."[76]



Regards,
Ed

Last edited by Ed J.; 03/12/14 09:11 AM.