My Thinkpad T400s runs at 8W/h when tuned with powertop2 (3g disabled, wlan disabled). But as the battery only has a capacity of 43Wh it only comes up to a bit more then 5 hours.
I could however replace the disk drive for another battery and have about 9 hours of run time with it.
I could however replace the disk drive for another battery and have about 9 hours of run time with it.