Hello, There appears to be a (serious) problem with Ubuntu's monitoring of the statistics (power, charge history, etc.) of laptop batteries. I have read several threads on Ubuntu forums regarding this issue, but to my knowledge they are only addressing this as a _software_ issue, particularly with gnome-power-manager. However, I believe this is a hardware issue as well.

For some particulars, I have an updated version of Hardy alongside Fedora 7 on a Dell Inspiron E1505. I have on several occasions ran Fedora on the battery for extended periods such up to 5 hours or more on long flights with still ample battery time left. However, no such luck in Hardy. In Hardy, when hovering over the battery icon in Gnome, I notice the power draining as usual, though perhaps a bit faster than in Fedora, although upon reaching 50% (after at most 2 hours on the battery), it immediately drops to 6% with no warning. Then the computer either hibernates or turns off depending on what settings I chose in the "Power Management Preferences."

What exactly is the state of the battery at this point? Is it truly dead as Hardy thinks, or is it somewhere slightly less than 50%? The battery itself thinks it's dead, as my battery LED comes on red when I push the power button to turn the computer on again, at which point nothing happens (ie the computer has no power to boot). Upon connecting the AC and booting into Fedora, it reports 1%.

What is the most discomforting, however, is the "Capacity" drops noticeably after each time this happens. So far, this has happened twice: initially the capacity was ca. 94%, and now it reads "87% (Fair)". At this rate my battery will soon be useless. Yet another reason to keep Fedora 7 going strong. I will only use Ubuntu on AC in the future.

Is there any way to verify e.g. the charge levels and capacity by other means than operating system-level applications? Also, is it possible to "hack" the battery to report a higher capacity (to let it charge more completely in the future)? Any thoughts?

Thanks...

(snapshot from gnome power manager)

Product: Battery Bay
Status: Charging
Percentage charge: 20%
Vendor: SMP
Technology: Lithium ion
Serial number: XXXX
Model: DELLRD8507
Capacity: 87% (Fair)
Current charge: 15.5 Wh
Last full charge: 75.8 Wh
Design charge: 86.6 Wh
Charge rate (raw): 27.9 W
Charge rate (smoothed): 18.2 W

I have also experienced this problem in my laptop. While some of the posts in the internet suggest to tune the power settings so that the power is used efficiently, even my observation is ubuntu is causing damage to the batteries.

I use Acer Aspire 5580 with ubuntu 8.04 running for over an year now, the battery life has completely gone now and it stays only for 5 to 10 mins. While a similar laptop purchased at the same time running windows, has good battery power after an year.

I run Debian on my Dell inspiron 8100 (What 7 or 8 years old now ?) and don't seem to have those issues with battery life. amazing considering the age of the battery/batteries in there.. (depending on how many bays I have batteries in at the time.)

Some batteries have a button on them you can press to get a visual indication of charge level by lighting up several LED's on the battery itself like a bar graph.

I don't know of any way to 'supercharge' batteries so their charge will last longer, although the Lenovo laptops have some sort of battery charge management software in windows 'to extend battery life'. by which I think they mean how many years wit will run before the battery needs replaced. I'm on the THIRD battery for that laptop and it's only 2-3 years old, so I don't have much faith in that application since it doesn't appear to have helped anything.

My battery does have an LED indicator which I never noticed before. It has 5 LEDs, so I assume each approximates 20%. But the readings from this as well as gnome power manager are not even remotely close. As far as I can tell, gpm is at fault when it drops erratically upon falling to 50%, as the LED indicator is well below that for quite some time. I have cleared out the battery cache so I have no clue what gpm is querying to get this data. Further, the "Last full charge" reading drops from day to day even when no battery discharge occurred. However, I am in no way retracting my opinion of Ubuntu shortening battery life--ever since I started using Ubuntu without AC power my battery is definitely experiencing a very quick death; to quantify, I only get about 1/3 as much time as I was getting just a few weeks ago.

No good answers to offer you just some rsources to review..
http://www.phoronix.com/scan.php?pag...ery_life&num=1
http://www.berthon.eu/ice_and_fire/?p=84
http://www.iuselinux.com/2008/10/ext...ntu-using.html

Battery issue in Ubuntu seems to have been around for quite a while..
https://bugs.launchpad.net/ubuntu/+s...er/+bug/120258



Man Google is flooded with hits on Ubuntu batter life.. Averyone seems to have a different approach to power saving battery life.. yikes