Computer Battery Power May Drain Faster with USB Device Attached

• Microsoft Windows 95
• Microsoft Windows 98
• Microsoft Windows 98 Second Edition

SYMPTOMS

Battery-powered computers that use Advanced Power Management (APM) or Advanced Configuration and Power Interface (ACPI) may experience increased power consumption leading to a more rapid drain of battery power when a Universal Serial Bus (USB) device is attached.

CAUSE

The bus activity required to maintain communications with the USB device prevents the Central Processing Unit (CPU) from switching to the C3 (Clock-Stopped) power state. When a USB device is not connected, the CPU can spend a significant amount of time in the C3 state, which reduces power consumption and extends battery life.

The option to turn off USB devices after a computer is idle for awhile but still in an active (not standby/suspended) state is not supported in the versions of Windows listed at the beginning of this article

WORKAROUND

To work around this issue, try to conserve battery power using any of the following options:

• Disconnect all USB devices if you are not using them.



• In the Power Management tool in Control Panel, adjust the power scheme settings to use shorter time-out values for turning off the monitor and hard disks and placing the computer in a system standby state.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article.

Additional query words:

Keywords : win95 win98 win98se
Version : WINDOWS:95
Platform : WINDOWS
Issue type : kbprb