[ltp] poll: battery life under T43

[Jiang Qian]

Hi All:
I've been tinkering to get the battery lifetime longer on my laptop and 
would like to see people's mileage. 

I have a T43(2668W12) with 1.86GHz Dothan, ati X300(M22 chip)  Hitachi  
7200rpm hard drive and 6cell battery(capacity 51840mWh). I use ubuntu 
hoary and a kernel 2.6.12.4 and 0.11 of ibm_acpi.  I patched the kernel 
ata drivers to get suspend to ram working

What I did to get conserve power: enable dynamic clock xorg, put scaling 
governor to conservative(which pretty much keep my computer at 800MHz).  
I don't use laptop mode because I worry about the repeated spin up and 
spin down destroying HD. 
Now some number. I got 17W(3 hours 3 min) if I put screen to dimmest 
and turn the fan off. Although I worry turning the fan off what the 
heat does to battery(with fan on temperature stabilizes around 54C for 
both CPU and GPU and 44C 38C for battery and 38C for HDD. With fan it 
does some kind of cycle between 55 and 65C)
With fan on and screen to brightest I have 20.3W, i.e. 2hour 33 min.
With fan off and screen to brightest I have 19.8W 2hour 37 min.
All these are down under gnome and with only light typing, not even web 
browsing. This is much lower than 4.5 hour as they advertise!

What else I can do to prolong battery time? What kind of number shall I 
expect? I got some ideas from
http://www.sas.upenn.edu/~vbraun/computing/T41/power.html
Although given my computer's more powerful chip should I expect less 
battery lifetime than he got? Any more optimization I can do?
Thanks a bunch!
Jiang