How to Reduce USB Voltage
As a popular method of connecting gadgets to a computer, maximizing the use of a computer's Universal Serial Bus (USB) ports also means drawing more power for the computer. A USB port can provide up to 5 volts of power and current anywhere in between 100mA (milliamperes) to 500mA. It is possible to configure the port to output less power, which is especially helpful when limiting USB access to external devices on the computer and conserving battery power on a laptop.
Click "Start" in your computer's lower left screen, then select the "Control Panel" option from the drop-down menu that appears.
Click the "Hardware and Sound" icon from the "Control Panel" window that appears.
Click the "Device Manager" icon under the "Hardware and Sound" window.
Click the arrow right next to the label "Universal Serial Bus Controllers." This allows you to expand the tree that provides you different options for all your computer's USB controllers and USB root hubs (USB ports).
Right-click the exact "USB Root Hub" you want to change. Usually, a desktop or laptop computer has at least two USB root hubs or USB ports available.
Click "Properties" to show your selected USB port's "Properties Dialog Box."
Go to the "Power" or "Power Management" tab in the dialog box, then choose your desired settings to restrict the USB port's power. Use the checkboxes to select any of the available settings.
Click the "OK" button to confirm the change you made.
Repeat the process if you want to reduce the voltage of the other USB ports in your computer.
Tips & Warnings
- There is also an option to actually turn off the power to a USB port. This way, you can temporarily make a USB port non-operational. You can always turn it back on anytime you want to use it again.