Re: PowerTop on Debian Stretch
On Wed 10 Feb 2016 at 11:32:48 (+0530), Jos Collin wrote:
> Hi, I'm not answering your question. But my suggestion is: don't bother about
> your battery life. Because even if you get 10 hours now, it is going to reduce
> slowly and reach 30 mins or 10 mins with in a few years. Then you have to
> replace your battery with a new one.
>
> I had a battery that drains to 0% with in 30 secs. I replaced that in 2012 with
> a 9 cell battery, when I started traveling with my laptop. The new battery also
> drains to 0% within 30 secs now.
>
> So I advice you to forget about battery life and move on to other important
> things. :-)
The (small size) battery on this laptop contains 42Wh fully charged.
Discharging it in 30 seconds would generate 5kW which is two
high-power electric kettles in the UK, over three in the US.
So either your battery hasn't charged properly, or else it's not
discharging properly, probably because there's a duff cell. In the
latter case, the battery remains a hazard because it still contains a
lot of charge if only it could find a discharge path.
> On 10-Feb-2016 11:05 AM, "Dwijesh Gajadur" <dwijesh1@gmail.com> wrote:
> I have a Dell Inspiron 5559 laptop which has a 40WHr, 4-cell battery. On
> Windows 7 I get a battery life of 6-7 hours. On Ubuntu I get a battery life
> of 5 hours after using PowerTop.
> However on Debian I get only 3 hours of battery life. I have done
> calibration several times and for several hours but I get only 3 hours of
> battery life.
If these timings can be achieved at will, I'd be interested to know if
the laptop was running at the same temperature on the various OSes. A
poor video driver might waste a lot of power. I suspect this is the
case with my own Dell laptop; given the chance it would make a cuppa.
I occasionally see the CPU at 96.5°C.
> My Question is, is it normal to get the lines:
> □ Cannot load from file /var/cache/powertop/saved_parameters.powertop
> □ Devfreq not enabled
> Is it because of these lines that PowerTop is unable to extend the battery
> life?
> Debian Stretch is currently using PowerTop version 2.8 and I heard
> somewhere on a forum that there is a bug in the 2.8 version. Is it true
> that there is a bug ? And is it that bug which is causing the problem?
Does https://bugs.debian.org/cgi-bin/pkgreport.cgi?dist=unstable;package=powertop help?
Cheers,
David.
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