Deep Discharge et al.

Nick Guenther kousue at gmail.com
Wed Dec 19 22:17:10 CET 2007


On Dec 19, 2007 4:05 PM, Fabian Olesen <firewalkerx at gmail.com> wrote:
>
> On Dec 19, 2007 5:20 PM, Nick Guenther <kousue at gmail.com> wrote:
>
> >
> http://wiki.openmoko.org/wiki/Neo1973_Battery_Charger#Neo1973_emergency_charging
> > is unclear about how the battery management works exactly.
> > "NOTE: Please do not press the power button before you have waited for
> > something like four hours. If you do so, the phone might [partially]
> > power up, and draw more power than the 100mA supplied by the
> > charger/USB, and so begin discharging itself again."
> > Indeed, sometimes I've left my neo turned off and plugged in for a few
> > hours, then I will turn it on and see that it claims 50% charge, and
> > then, even while still plugged in, it will discharge itself and go
> > flat. Other times I've left it charging for longer and then have
> > plugged it in and then it charges to full.
> > So my question is: is there a minimum level of battery charge needed
> > in order to support fast-charge?
> >
> > The times it's gone flat on me I may only have been charging from
> > 100mA. I'm not sure.
> >
> > -Nick
> >
> >
> Does the neo actually know how much power is left in the battery?

Well, it knows whatever the apm subsystem reports. That part is pretty
accurate, the inaccurate part is the attery's own measurement of
itself. This is a general problem with batteries, and not the neo...
except I don't know how good the neo's detection is afterall, can
anyone on the hardware team comment on that?

> if yes, then i would say it would be a good idea to set the device to
> shut down when there is 5% left (remembering to turn of the gsm as well.
> that should remove the need for the many deep discharges, and would
>  have us up and going faster again with the neo.

Yes.. well.. see bug #1003
(http://bugzilla.openmoko.org/cgi-bin/bugzilla/show_bug.cgi?id=1003)
:/



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