[Solved] UX21A seems to overcharge battery

Question

I have an Asus  Zenbook UX21A with Archlinux x86_64 fully up to date, where I have the following situation:
The charging cable has an LED which turns from orange to green when the battery has been fully charged.
And it does, BUT when I do
cat /sys/class/power_supply/BAT0/{energy_now,energy_full}
the value outputted for energy_now still keeps rising well above the value of energy_full and does not stop.
After about 5 minutes of keeping the laptop on AC after it having been completely charged
the value of energy_now already rises to about 105% of the value of energy_full.
Now I'm not sure if something is wrong and the battery keeps getting forefully overcharged or if it is
an error in the value being outputted.
Has anyone ever encountered this behaviour with this laptop model or any other and knows whether
this is simply a display error?
Last edited by Calrama (2013-02-23 11:28:58)

Answer 1

For other users encountering this later:
After several reboots and a fair time completely without power in between the energy_now counter now
stops at about 101.99% of energy_full.
That in itself is still strange, but at least it seems to only be a display bug and no actual overcharging
occurs. The exact values (when fully charged) are:
/sys/class/power_supply/BAT0/energy_full: 35520000
/sys/class/power_supply/BAT0/energy_now: 36230000