ACPI sleep power drain test script

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Revision as of 17:39, 31 July 2005 by Evan.heidtmann (Talk | contribs) (Add note about second battery)
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The following script will suspend your notebook to ram and output some statistics about the power drain during suspend to /var/log/battery.log. The output will look something like this:

Di Jan 11 14:01:15 CET 2005
before: 41170 mWh
after: 41000 mWh
diff: -170 mWh
seconds: 1671 sec
result: -366 mW
Congratulations, your model seems NOT to be affected.
This is not totally reliable, e.g. on some (all?) R32 the values

reported by ACPI for the battery are wrong by a factor 10, i.e. they are actually reported in cWh instead of mWh. Thus the script thinks that the power consumption is only a tenth of its actual value.

This script assumes you have only one battery. If you have a second battery (for example, an UltraBay Slim battery), take it out for this test or change occurrances of "BAT0" in the script to "BAT1". If you do the latter, you will get bogus results if the second battery is run down while sleeping.

Please save this script to a file, i.e., make it executable (chmod +x and execute it as root while your notebook is on battery. To get representative values you should leave the notebook suspended for at least 20 minutes.

# test script for measuring power drain during suspend-to-ram with ACPI

# remove USB for external mouse before sleeping
if lsmod | grep '^usbhid' >/dev/null ; then
   /sbin/modprobe -r -s usbhid
if lsmod | grep '^uhci_hcd' >/dev/null ; then
   /sbin/modprobe -r -s uhci_hcd
if lsmod | grep '^ehci_hcd' >/dev/null ; then
   /sbin/modprobe -r -s ehci_hcd

hwclock --systohc

date >> $LOG
DATE_BEFORE=`date +%s`
BAT_BEFORE=`grep 'remaining capacity' /proc/acpi/battery/BAT0/state | awk '{print $3}'`
echo "before: $BAT_BEFORE mWh" >> $LOG

echo 3 > /proc/acpi/sleep

DATE_AFTER=`date +%s`
BAT_AFTER=`grep 'remaining capacity' /proc/acpi/battery/BAT0/state | awk '{print $3}'`
echo "after: $BAT_AFTER mWh" >> $LOG

DIFF=`echo "$BAT_AFTER - $BAT_BEFORE" | bc`
echo "diff: $DIFF mWh" >> $LOG
echo "seconds: $SECONDS sec" >> $LOG
USAGE=`echo "($DIFF * 60 * 60) / ($SECONDS)" | bc`
echo "result: $USAGE mW" >> $LOG
if [ $USAGE -gt -1000 ]
    echo "Congratulations, your model seems NOT to be affected." >> $LOG
    echo "Your model seems to be affected." >> $LOG
if [ $SECONDS -lt 1200 ]
    echo "!!! The notebook was suspended less than 20 minutes." >> $LOG
    echo "!!! To get representative values please let the notebook sleep" >> $LOG
    echo "!!! for at least 20 minutes." >> $LOG
echo "" >> $LOG

if !(lsmod | grep '^ehci_hcd') >/dev/null ; then
   /sbin/modprobe -s ehci_hcd
if !(lsmod | grep '^uhci_hcd') >/dev/null ; then
   /sbin/modprobe -s uhci_hcd
if !(lsmod | grep '^usbhid')   >/dev/null ; then
   /sbin/modprobe -s usbhid

hwclock --hctosys

The script was originally written by Jan-Hendrik Benter and was modified a little for this page.