battery charging and discharging graphs
Harald Koenig
koenig at tat.physik.uni-tuebingen.de
Tue Aug 26 18:50:31 CEST 2008
On Aug 22, Jozef Mlich wrote:
> i have made a couple graphs of battery charging and discharging.
I hate those "me too"-mails -- but here I go: me too ;-)
> So in case you are interested a have published my results on my blog:
> http://joejoe.blog.root.cz/2008/08/22/vydz-baterii-ve-freerunerovi/ . There
> are a few words in Czech which you can just skip. The graphs was made on
> fso-testing image from 20. August 2008 with disabled "Suspend" and with
> turned on gps and wifi. On the blog are also links to script which generates
> graphs.
very interesting! I started to collect battery data too, to get an idea
what's alreay possible (and what might be possible).
here is a PDF with 3 (gnu;)plots (data etc. available on request):
http://www.tat.physik.uni-tuebingen.de/~koenig/bat1.pdf
plot 1: 3 charge/decharge runs with no suspend (two with 500 mA from notebook
and one with 1000 mA AC charger).
decharging is with different display brightnesses (low/high/off).
plot 2 and 3 show decharging while being suspended (or trying to be so;),
sorry for different X scaling...
for plot 2+3 I use a "atd" script which collects data, triggers the next job
in "now + 10 minutes" and suspends the OM again (see below).
what worries me in plot 2+3 right now is the fact that suddenly during night
the decharging rate significantly increases (see 24h and and 55h
in plot 2, 5400 min and ~5800 min in plot 3!).
the extrapolation for the 1st decharge in plot 2 shows an estimated
"uptime" (being mostly suspended though;) of ~50+ hours with a
wakeup every 10 minutes -- wouldn't be that bad, but it's only
an extrapolation and I never managed to get any close to that "uptime"
so far as the plots show:-(
the OM alyways was "as idle as possible" (running Om 2008.8 with zecke-dev updates).
at least one time there seemed to be problems with suspend, I got
lots of "apm: can't suspend -- device or resource busy" (or similar)
messages in logread or dmesg output.
but for the last decharge in plot 3 (5600-6150 min) I just picked up the OM
at 1 % before crashing and here "apm -s" still worked fine, so there has to
be another reason for that increase in power usage during night.
more details about that last run which I just noted while collecting
data for another problem (see devel-list subject: Xglamo loops and hangs...):
that last run (5600-6150) startet ~23:00 (== ~5550), the bend at 80%
is around 03:30 in the moring (0% is 08:58).
now I noticed in "ps" output, that Xglamo got restarted at 06:40
for yet unknown reason. _maybe_ the reason for that Xglamo crash/restart
and the power usage have some common reason ? __maybe__ there was
a 1st Xglamo crash before at 03:30 when "something" happend which
increased power usage ?!?
just a thought, but no good idea how to further check/log such things.
any comments/ideas/suggestions ?
/var/spool/at/script-1 :
-------------------------------------------------------------------------------
#!/bin/sh
cd /var/spool/at
( date ; apm) >> /tmp/date.out
ln -s script-1 ` /home/root/now_plus 600 `.1
rm $0
echo `date +%s ; date ; cat /sys/devices/platform/bq27000-battery.0/power_supply/bat/capacity /sys/devices/platform/bq27000-battery.0/power_supply/bat/time_to_full_now /sys/devices/platform/bq27000-battery.0/power_supply/bat/voltage_now /sys/devices/platform/bq27000-battery.0/power_supply/bat/current_now ` >> /home/root/bat11.dat
echo >> trigger
sleep 1
# for interactive use, better comment out this "apm -s" and use the
# power management of illume....
#
apm -s
-------------------------------------------------------------------------------
to start the data collection once use
cd /var/spool/at
ln -s script-1 1.1
echo >> trigger
due to problems with shell arithmetic for time data in seconds ("dc" outputs
float values in exponential representation, "bash" crashes at startup when
used in "atd" scripts:-( I use the following small C program to
get the "next timestamp" for atd:
-------------------------------------------------------------------------------
/* now_plus.c */
#include <stdio.h>
#include <sys/time.h>
main(int argc, char *argv[])
{
struct timeval tv;
int i=0;
if (argc>1)
i = atoi(argv[1]);
gettimeofday(&tv,NULL);
printf("%d\n",tv.tv_sec+i);
}
-------------------------------------------------------------------------------
Harald
--
"I hope to die ___ _____
before I *have* to use Microsoft Word.", 0--,| /OOOOOOO\
Donald E. Knuth, 02-Oct-2001 in Tuebingen. <_/ / /OOOOOOOOOOO\
\ \/OOOOOOOOOOOOOOO\
\ OOOOOOOOOOOOOOOOO|//
\/\/\/\/\/\/\/\/\/
Harald Koenig // / \\ \
koenig at tat.physik.uni-tuebingen.de ^^^^^ ^^^^^
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