Battery Life

[iStealth]

Hi All,

I noticed some strange behavior of the batterry capacity on my nc10. When I check "Laptop Battery" (by clicking on the battery tray icon), the dialog with some extra information pops up and the "Capacity:" says "88% (Fair)". From the very beginning it was always "96% (Good)" and never more. I was wondering if the battery does die so quickly, I'm always running on batteries, except when I have to charge them. The laptop is only 3 weeks old. So, what is your experience ?

[voria]

IMO it's strange that it is on 88% already, after only three weeks.
Mine is 2 months old and it says 94%. However I always use the NC10 with AC connected when I'm at home.

You can try to use the 'battery calibration' option inside the BIOS to recalibrate the battery, I think it would be usefull and it should recover a little percentage.

[iStealth]

IMO it's strange that it is on 88% already, after only three weeks.
Mine is 2 months old and it says 94%. However I always use the NC10 with AC connected when I'm at home.

You can try to use the 'battery calibration' option inside the BIOS to recalibrate the battery, I think it would be usefull and it should recover a little percentage.

Hi,

I discharged the batteries completely and then used that "calibration" from BIOS, so now I'm back to 94%, when they are fully charged. I also noticed that on XP batteries last a bit longer, having 50%, ubuntu usually reports 2 solid hours and with XP it's more than 3. It can be quite subjective, but it looks like XP consumes less than ~9-10W (ubuntu rates). I ran "powertop" but it only detects high consumption on usb where my wireless mouse is located and from firefox. With my previous dell laptop and Arch linux the batteries actually lasted longer in linux. Hopefully some tweakes about that will appear for ubuntu as well.

[voria]

Well, you have to consider that windows xp puts the brightness to the lower level when in battery, while gnome power manager put it to 50% (both by default settings, of course). With brightness set to lower level on ubuntu too, powertop says the consumption is about 7-7.5W. So, changing settings for gpm would already be a good way to save more energy.
Another way to save energy is to set up laptop-mode to be more "energy saving friendless" than it is using the settings described in my howto.

[nero23666]

My Battery capacity is 92% percent now. but when i move the mouse over the battery icon it only says 5h even when wlan is off and the display is nearly complete dark. when i click on the icon it shows that the battery will last nearly 6,5h when the cpu is set to 800mhz powersave (wlan off, bluetooth off). i noticed that on windowsxp the battery lasts nearly 9h, could it be that the information is wrong or is my battery bad?
laptop mode is enabled

[stuartherbert]

Hi,

I'm consistently getting about 5h from my NC10 with the standard 6 cell battery; that's with bluetooth disabled, and either wireless enabled or USB mobile broadband device active. Power consumption varies between 10W and 15W, mostly caused by using Firefox.

Have you actually had 9 hours battery life when using Windows XP, or is that something you've read somewhere?

Best regards,
Stu

[nero23666]

Hey,
yesterday i brought my netbook back and got me a new one, the n110.
I hope it can use the same scripts from vorias repos.
Actually a friend og mine had windows runnign on an nc10 and when the brightness was nearly off and so wireless and bt, the battery status showed a bit more 9h when the cpu did nothing. i think this would go down until 6-7hours when u start at least lookin some movies.

[stuartherbert]

Actually a friend og mine had windows runnign on an nc10 and when the brightness was nearly off and so wireless and bt, the battery status showed a bit more 9h when the cpu did nothing. i think this would go down until 6-7hours when u start at least lookin some movies.

No wireless, bluetooth, and an almost-black screen ... what's the point of 9 hours battery life if you can't actually do anything productive on the machine to get there?

The Gnome battery applet that Ubuntu uses isn't very accurate with its estimate of remaining time. powertop is much better. I'm currently looking at the battery-applet code to see if it can be fixed or not.

Best regards,
Stu

[voria]

The Gnome battery applet that Ubuntu uses isn't very accurate with its estimate of remaining time. powertop is much better. I'm currently looking at the battery-applet code to see if it can be fixed or not.

I think it's not a bug but a feature.
To calculate the remaining time, gnome-power-manager uses a learnt profile instead of reading the current remaining time every time like powertop does. This feature can be disabled by setting to false the '/apps/gnome-power-manager/general/use_profile_time' gconf key.