M1330: Poor battery life in Ubuntu

Hey guys, I've been doing some research on this, but I can't get a straight answer. I'm running Ubuntu (Hardy Heron) on my XPS M1330, but I get really poor battery life, a bit less than 3 hours. I consider that bad because I have the huge 9-cell battery, and I get close to double the runtime in Vista. I'm also pretty new with Linux. It doesn't seem that the processor can be stepped down like in Windows. Do you guys know of any fixes for this? I appreciate any help, thank you!

 

That's pretty bad. But I think there may be ways to step down the processor...anyways, you should probably tweak the processes that are running.

In fact, I thought the CPU was downclocked by default, at least in Gutsy.

Anyways, check the Add/Remove Programs for those sorts of programs...

Thomas, if you're reading this, what's that program you said is good for paring down Ubuntu?

 

see what

cat /proc/acpi/battery/BAT0/info

says. it should show you something like below.

design capacity: 7800 mAh
last full capacity: 7860 mAh

if the last full capacity (last full charge) is close to 7800, you're doing good and you should be able to adjust your performance/battery options in ubuntu just like windows, with minor differences.

 

you must have the following essential stuff installed for power scaling in laptops to work

cpufrequtils (for cpu frequency scaling)

laptop-mode-tools (general laptop powers saving)

pm-utils (for suspending)


You might have them already installed, in terminal could you type in cpufreq-info and post its output here

 

Also make sure that the hdparm service is enabled (see Preferences/Administrator).

 

To dynamically change your clock speed, you can run the following command:

sudo dpkg-reconfigure gnome-applets

"Right-Click>add to panel" on the panel and select cpu frequency scaling monitor. You can change the clock speed by left-clicking on this applets. I have done this myself many things when I was using ubuntu without any problem. The disclaimer only warn you that you have the power to change the clock speed without root/sudo permission.

You can rerun the command again if you feel uneasy about what its telling you to do.

However, to achieve only 3 hour with a 9-cell seen really off. Have you drain the battery to 3 hour or only look at the battery meter? The battery meter can sometime be off (like windows) and the only real way of knowing how much battery life you have under linux is to try doing a drain test. For my m1330, the battery meter tells me I only have 3 hrs but in reality, I mange to get 3:30 (with little to 20 minutes left). I had the brightness on level 3, clock speed - powersave, and Ethernet cable plug in with wifi/bluetooth off. I also am not using laptop-mode (disable the utility).

By default, distro such as Ubuntu have your cpu default to ondemand for anyone wondering.