[TriLUG] apm gives wierd values for old battery
Joseph Mack NA3T
jmack at wm7d.net
Sun Dec 24 19:13:24 EST 2006
On Sun, 24 Dec 2006, Ed Hill wrote:
> Its been a while since I've used APM. For ACPI, the percent typically
> reported is the "percent of the last full charge" not the "percent of
> the battery design capacity". Initially, the two percents are about
> equal. But, over time, most batteries slowly loose the ability to hold
> charge so the reported percentage is a fraction of an ever-decreasing
If I understand you, we both agree. The battery after
charging will show 100% and then decrease to 0% (if you let
it go that far) as you use it. The change with age is that
100% represents progressively decreasing number of mAh.
I have a (laptop - new battery) pair that shows this
behaviour, indicating that the bios (or whatever apm reads)
in the laptop is behaving OK. I get about 3hrs out of the
battery with apm showing 3% charge left.
With the old battery, the laptop takes about 30mins to
get to 73% charge, when the laptop hibernates. I would
expect if the battery had reduced capacity, that it would
show say 10% in 30mins.
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
generator at http://www.wm7d.net/azproj.shtml
Homepage http://www.austintek.com/ It's GNU/Linux!
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