Super User is a question and answer site for computer enthusiasts and power users. It only takes a minute to sign up.
Sign up to join this community
I'm looking to limit the amperage output Windows gives to usb devices through a certain port. I'm finding Windows is providing 500mA to devices that only operate on 100mA or lower, which is consuming excess battery life.
The device on the left is my USB mouse which hasn't shown up. It only requires 50mA to operate, and it is being provided 500mA.
USB ports are voltage sources, not current sources. That means the actual current drawn is exactly how much a device needs for the voltage to stay at 5 Volts. No excess current will flow.
The current values shown are in the USB descriptors, enabling the OS to detect over-current situations (too much high power stuff plugged) in bus-powered hubs.
