XO power management

David Van Assche dvanassche at gmail.com
Sat Apr 2 07:14:46 EDT 2011


Sounds like someone we really really need to help out with the power
problems we have been havingf throughout SA.... These problems already
originated in España so I wouldn't be surprised if there is a link...

who knows, maybe we can fix it in a couple of days....


optimism ALWAYS amigo!

kindr regards,
David 'nubae' Van Assche

On Thu, Mar 31, 2011 at 9:43 PM, Ismael Schinca
<ischinca at plan.ceibal.edu.uy> wrote:
> 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
>
>
> _______________________________________________
> Devel mailing list
> Devel at lists.laptop.org
> http://lists.laptop.org/listinfo/devel
>
>


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