XO power management

Thu Mar 31 15:43:01 EDT 2011

Richard, Ceibal about to start working heavily in reworking how to classify
used batteries. Due to the number of batteries involved, we were asked to
devise a "good enough" procedure to estimate the battery condition in less
than 10 minutes. The plan would be to get several parameters from the
batteries and try to estimate it's condition based on them. Have you been
able to analyze the results from the logs I sent you?

Another question. Is there information in the battery controller regarding
total number of charge/discharge cycles?

Thanks!
Ismael

2011/3/30 Ismael Schinca <ischinca at plan.ceibal.edu.uy>

> Ok. Better late than never.
> Attached here are the logs from the XO batteries.
>
> Each file has one .csv log with the battery serial at the end of the file
> name given by the olpc-pwr-log.
>  The tests were all run simultaneously even though some timestamps are off.
>
> There are two logs for each battery. The first one chronologically is the
> one corresponding to the battery discharging and the second one is for the
> charging process.
>
> There were two XO with a brand NEW battery, with a label NEW at the end of
> the file names and two tests run with really OLD and badly shaped batteries,
> labeled OLD. The rest are from old but "good enough" batteries.
>
> Caveat: the charging tests were done with the xset -dpms not set due to
> some miscalculation, so the screen went off some times. Sorry about that.
> The discharging process went as planned.
>
> I haven't had time yet to analyze the logs, so I don't have comments
> regarding the results.
>
> Cheers!
>
> 2011/3/24 Paul Fox <pgf at laptop.org>
>
>> ismael wrote:
>>  > OK. Great. Is the attached version newer than the one in Sugar 0.88??
>>
>> almost certainly.
>>
>> paul
>>
>>
>>  > Because the latest dextrose image is mainly based on Sugar 0.88
>>  >
>>  > 2011/3/24 Richard A. Smith <richard at laptop.org>
>>  >
>>  > > On 03/24/2011 10:41 AM, Ismael Schinca wrote:
>>  > >
>>  > >  I'm planning to use different XO's, all of them 1.0 hardware. I
>>  > >> definately won't be able to finish today because they all have
>> different
>>  > >> OS images and I think it would be best if I update them all (even
>> for
>>  > >> future tests). Maybe tomorrow, maybe monday.
>>  > >>
>>  > >
>>  > > Yes certainly please use the same image on all of them.  If you have
>> to
>>  > > install software then please use the latest version of olpc-pwr-log.
>>  I have
>>  > > it attached to this mail.
>>  > >
>>  > >
>>  > >  I think it will be very hard to perform the same test under the same
>>  > >> conditions as you suggest because:
>>  > >> - It will be very time consuming (though it doesn't need a lot of
>>  > >> attention during the test)
>>  > >>
>>  > >
>>  > > My goal is to automate the test and use a very short test window.  ie
>> 20
>>  > > minutes or so.
>>  > >
>>  > >
>>  > >  - The air conditioning in our building is quite frankly chaotic so
>>  > >> temperature is really variable (which is actually a lot worse for us
>>  > >> humans than batteries ;) )
>>  > >>
>>  > >
>>  > > Yes. Sorry my use of the word exactly was probably too strong.  I
>> don't
>>  > > mean that it has to be 25 degC ambient and only that temperature.
>>  The temp
>>  > > fluctuations in a air conditioned office should be within reason. I
>> just
>>  > > don't want the profiles generated in an office and then the test run
>> in a
>>  > > outside warehouse at 33C.  Or the curves generated on a XO-1 with
>> build 8.2
>>  > > but the test run on a 1.5 with build 10.1.3. That sort of thing.
>>  > >
>>  > >  The closer I might get, which I think could be pretty close is:
>>  > >> - Install the SAME fresh OS image and firmware version on all the
>> test XOs
>>  > >> - Disable power management in every XO.
>>  > >>
>>  > >
>>  > > and dpms. xset -dpms from the sugar terminal other wise the screen
>> will
>>  > > turn off in 20 minutes and change the power draw.
>>  > >
>>  > >
>>  > >  - The laptops batteries are mostly charged, so it will be a charge
>> after
>>  > >> discharge, so I think temperature there is less of a concern
>>  > >> - Run the tests at the same time in every XO
>>  > >>
>>  > >
>>  > > Yes.  I believe that will work fine.
>>  > >
>>  > > Note: I'm getting on a plane in a few minutes so this will be my last
>>  > > e-mail until much later on today.  Possible tonight or tomorrow.
>>  > >
>>  > >
>>  > > --
>>  > > Richard A. Smith  <richard at laptop.org>
>>  > > One Laptop per Child
>>  > >
>>  >
>>  >
>>  >
>>  > --
>>  > Ismael Schinca
>>  > Centro Ceibal - Depto. Técnico - I+D
>>  > Avda. Italia 6201 - Edificio Los Ceibos
>>  > Montevideo - Uruguay.
>>  > Tel.: 2601 57 73 Int. 2232
>>  > part 2     text/plain                 129
>>  > _______________________________________________
>>  > Devel mailing list
>>  > Devel at lists.laptop.org
>>  > http://lists.laptop.org/listinfo/devel
>>
>> =---------------------
>>  paul fox, pgf at laptop.org
>>
>
>
>
> --
> Ismael Schinca
> Centro Ceibal - Depto. Técnico - I+D
> Avda. Italia 6201 - Edificio Los Ceibos
> Montevideo - Uruguay.
> Tel.: 2601 57 73 Int. 2232
>
>

-- 
Ismael Schinca
Centro Ceibal - Depto. Técnico - I+D
Avda. Italia 6201 - Edificio Los Ceibos
Montevideo - Uruguay.
Tel.: 2601 57 73 Int. 2232
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