Last year I purchased an Advent 7074 laptop, which as you can guess came shipped with Windows XP. This was changed about a month later to Ubuntu, and has again been changed to Debian, for other reasons that aren't really relevent here. :-)

However, whilst I seem to have everything working OK on this laptop (although some items such as the Firewire I can't test because I don't have anything to utilise it, or the Infrared that is proving to be a major headache) the battery and OS seem to be having a lovers tiff of sorts.

Under Windows, on the standard Lithion Ion battery shipped with this model, I could easily manage 3:30 in usable time. Under Ubuntu, I still managed between 3:00 and 3:15 on average. And on Debian? 47 minutes!

All of these times assume the following:

* WiFi is not in use
* CD-RW/DVD-RW drive is not active
* Audio is inactive and muted
* Infrared is off
* There are no power-heavy devices attached such as USB mice
* The screen backlight is dimmed to the minimum

So, the comparison is fair, imo. Tbh, when i'm using it on a battery i'm normally somewhere away from an AC source and primarily concerned with getting my work done - not listening to music etc anyway - i didn't buy a laptop for it to just sit on my desk and gather dust.

When I installed Ubuntu, I cannot recall having to do very much to attain a reasonable battery life. Under Debian however, i've tried various things with varied results:

- Powernowd and cpufrequtils are installed and seem to be working
- Hdparm is installed, but from the sound of it the HDD continues to spin anyway
- The CPU fan acts like it's on crack, constantly - i've tried installing lm-sensors and the relevant i2c modules but not succeeded
- I've read about an application called varyfan in another discussion, but can't seem to install it (apt-get seems to fail in this respect)

Additionally, the battery's design voltage is 10,800 mV, and the system is currently running it at between 25,700 and 30,000 mV! This together with the revelation (through 'cat info state' in /proc/acpi/battery/BAT0) indicates that only 66% of the battery's capacity is being charged.

Any help with this would be appreciated...

MD