Increase your laptop battery life by up to 25% for FREE

[elty]

Apperantly Windows XP has a bug (again). If there is a USB device pluggin to the laptop, the CPU will fail to fall into deep sleep, thus increasing the power consumption. By applying the fix, a Thinkpad T43 was able to recover almost 70 minutes of battery life.

Check page 3 for the registry fix. Apply at your own risk!
http://www.anandtech.com/mobile/showdoc.aspx?i=2693

Interestingly (or unsurprisingly) the bug is documented/last update on July 2005, but nothing has been released to the public yet.

[coriolis]

Only for Centrino Duo isn't it?

edit: Or not. Interesting...

[winner2000]

Only for Centrino Duo isn't it?

Yuppers...as far as I understood anyways.

[ynchu]

And you can always turn down the brightness of your monitor, that gives you 25% for free, too! :D

[jm20]

I think you mean USB 2.0 device, iirc USB 1.1 devices do not suffer from the Windows XP ACPI state driver issue. Just use a USB 1.1 mouse and your good, unplug all USB 2.0 devices when not in use. Just wait for a real MS fix in the meantime instead of playing around with mickey mouse solutions.

[skanji]

why not unlpug whatever devices are in your laptop? chances are if you are turning off your laptop, you are on the move...