gnome-power-statistics shows bogus "Energy when full" value

[Reuben Thomas]

gnome-power-statistics sometimes gets the wrong value for Energy when full, causing the battery indicator to show nearly empty when it's nowhere near empty.

For example:

slice 14:29:01 ~$ cat /sys/class/power_supply/BAT0/energy_full
67410000
slice 14:31:52 ~$ cat /sys/class/power_supply/BAT0/energy_full_design
67000000
slice 14:31:57 ~$ cat /sys/class/power_supply/BAT0/energy_now
28310000

Meanwhile, gnome-power-statistics is correctly showing Energy (design) as 67.0Wh, but Energy when full as 633.7Wh, roughly a factor of 10 too high. Interestingly, although it then calculates that the battery has about 6.1% left, it still shows the time remaining correctly (about 2 hours).

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: gnome-power-manager 3.2.1-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
Date: Thu Nov 17 14:28:44 2011
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
SourcePackage: gnome-power-manager
UpgradeStatus: No upgrade log present (probably fresh install)

[Reuben Thomas (rrt)]

This bug seems to be fixed in precise.

[Reuben Thomas (rrt)]

I am seeing this bug again with kernel 3.2.0-20, where for example I found a battery 65% full (by calculating with the numbers found under /sys/class/power_supply/BAT0) was reported on the desktop as 7% full (a factor of 10 too small), but with the correct (several hours) remaining life time.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[franglais.125 (franglais.125-deactivatedaccount)]

Hi,

I hope someone is still following this bug.

I have a fresh installation of Ubuntu 12.04, with all the updates done.
I own a Dell Vostro V131.

I too get the wrong "Energy when full" value, around 80 % of the time.

gnome-power-statistics shows the correct "Capacity" of the battery (91.8 %), and the correct "Energy (design)" (65.0 Wh) values.

However, when the battery is full, the value for "Energy when full" is almost always 65.0 Wh. As soon as I unplug my computer, the battery indicator shows 91 % of battery remaining.

This indicates that the battery indicator does indeed show the correct battery percentage left, but when measured against the designed energy, and NOT the energy when full, which is misleading.

On the other hand, at least this implies that it shows the correct Remaining time.

Please let me know if you need more info. I hope what I wrote can help...

[Reuben Thomas (rrt)]

This bug still occurs intermittently in quantal with kernel 3.5.0-17-generic.