Document with answers to most popular battery-related questions is ready

Wolfgang Spraul wolfgang at
Sun Aug 2 21:18:46 CEST 2009


> Wolfgang, please consider making current measurement in suspend
> easy. :)

Yeah - I thought that's what we were talking about :-)
I'm not sure about your TP/DMM/EE advice.

Isn't the Coulomb counter the perfect way to make precise data available to
everybody? That was the point I was trying to get to.
If not CC, what are the alternatives? Test points don't sound right to me.
Precise current measurements maybe, but only if they are precise enough and
can really serve the same purpose as the CC.


On Sun, Aug 02, 2009 at 11:05:18PM +0400, Paul Fertser wrote:
> Michal Brzozowski <rusolis at> writes:
> > 2009/8/2 Wolfgang Spraul <wolfgang at>
> >
> >     Hmm, that's a pretty strong statement.
> >     At Openmoko we spent _a lot_ of money combined to get this CC thing to work.
> >     The theory was that you have it in most notebook batteries so it's 'a good
> >     thing to have'.
> >     But if it's not actually used, then it would be one of those many things
> >     we did that should have been better thought through.
> >
> > No, I think it was a very good decision. Not only low-level
> > programmers need it, but also normal* users who want to know how
> > long the battery lasts with certain configurations. I know for
> > example that with gsm on it lasts about 50h in suspend, with gsm off
> > about 100h
> Hm, there's probably something very wrong with your config, no?
> With GSM on in suspend it should last for 140 hrs and with off it
> should be even more.
> Hm, so basically your point is that CC allows current measurement in
> suspend. Ok, but if there're convenient TPs you can use your DMM to do
> the same as well. Also you can do that by connecting the device via
> DMM to a lab PSU or a pack of AA batteries. Moreover, there's quite a
> limited number of usecases (wrt power-management) so those who has
> some EE skills can do the measurements once and then share the info
> for everybody.
> Wolfgang, please consider making current measurement in suspend
> easy. :)
> -- 
> Be free, use free ( software!
> mailto:fercerpav at
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