How long laptop battery should live ?

[Ian Smith]

On Wed, 24 Nov 2010, David DEMELIER wrote:

 > Thanks for all your answers, I guess my battery is getting on its end of life..
 > 
 > After running 30 minutes on battery, the percent is still 100% while
 > the remaining time is slowly decreasing.. Aaaah buying a new battery
 > costs around $134 !

Despite what its internal chip [mis-]reports, how long will it actually 
run on this battery with a moderate or no load?  Watching actual battery 
voltage, say once a minute as it runs down, or while charging, will give 
you a much better idea of real condition.  I tend to run something like:

% cat ~/bin/t23loop
#!/bin/sh
[ "$1" ] && sleep=$1 || sleep=60
while true; do
        t23stat | tee -a ~/t23loop.out
        sleep $sleep
done

% cat ~/bin/t23stat
#!/bin/sh
echo -n "`date` "
sysctl dev.cpu.0.freq dev.cpu.0.cx_usage
sysctl dev.acpi_ibm | egrep 'fan_|thermal'
sysctl hw.acpi.thermal.tz0.temperature
acpiconf -i0 | egrep 'State|Remain|Present|Volt'

.. but just logging date and the acpiconf would be enough for this.

Have you tried one round of the battery meter conditioning I mentioned, 
to see if it shows any improvement?  Worked for me, anyway <shrug>

 > I think I could live a few months before buying a new one but it sucks :-/

Clues to save power may be helpful but don't really address this issue; 
still, one of the best is http://wiki.freebsd.org/TuningPowerConsumption

cheers, Ian