Hi Jason
being the author of GNUstep's batmon and being owner of several laptops
and having developed and tested on them, I have some un-authoritative
information.
Jason Adams wrote:
Upon, pulling the plug from the wall on my older Toshiba Satellite (which has a
new-ish battery)
both xfce4 and apm agree while reporting declining battery power down to about
85%
The problem here is "new-ish".
The behaviour you describe is typical of a dying battery and/or a
screwed-up power management chip.
Just some questions:
1) define newish. How old and if you know how many cycles?
2) Is it original or a "genuine replacement"
anything which has > 6 months or 50-100 cycles is not new anymore.
Good batteries (which might be "luck", quality of elements, how well
they are paired and other factors) will work and perhas age very
gracefully for the years to come.
Bad batteries start showing "jumps". I think this is most often due to
elements being mismatched.
Usually manufacturer batteries are better than cheap ones from China,
but I also had the opposite experience!
then both fall off a cliff and immediately indicate 8% and start warning about
imminent battery
exhaustion.
85% to 8% in the blink of an eye. And nothing in between.
If I plug it back in, let it charge for a 10 minutes, it will be back up around
24%.
If I again unplug, it will drop roughly in a linear fashion. with no sudden
drops.
This seems like a bug in what ever apm and xfce4 use to obtain readings.
Any clue where I should start looking for this?
Do you have a way of knowing the battery status without using the OS?
For example, you might have a battery led that starts blinking or gets
orange at about 5%. Will it turn on after say 10 minutes apm reports
your battery to 8%? Most probably it is then not an OS/apm/software bug.
Perhaps your battery has LEDs showing its charge or you can access it
from the bios. E.g. certain DELL laptops allow that (thus reboot and check).
When it is 8%, how long can it actually run? then what happens BIP or a
LED turns on?
Sadly, I did not port yet batmon.app to ACPI on OpenBSD so it will just
say the same thing as "apm" does, so no cell health data info.
Riccardo
