dead battery

[Vince M. Clark]

Well, I'm out of options. I left my fr plugged into the trickle charger overnight. Still won't boot. 

Then I read this last post, about removing the battery long enough for a reset, plugging into USB for 5-10 min, unplug/pause/plug back in. Still won't boot. 

The only thing I haven't done that was recommended in this last post is to use the latest u-boot. Unfortunately I cannot do this until I get it to boot. Guess I will wait for my external charger to arrive. 

Should I be concerned that this isn't just a battery issue and maybe my fr is dead? 

----- Original Message ----- 
From: "William Kenworthy" <billk at iinet.net.au> 
To: "List for Openmoko community discussion" <community at lists.openmoko.org> 
Sent: Wednesday, October 1, 2008 12:01:52 AM (GMT-0700) America/Denver 
Subject: Re: dead battery 

These are my understandings from lots of reading and previous posts 
between myself and Andy Green and others on the subject - should all be 
in the archives. With 2007.2 I was hit one out of every 3 overnight 
suspends ending in a flat battery. At least with 2008.9 its rarer (but 
does happen :( 

With the later u-boots, usb default is 100ma as soon as its plugged in. 
This unfortunately is less than a running Fr needs. Normally as soon as 
the operating system is up enough, it will negotiate up to 500ma with 
the host, or in the case of the wall charger, read the sense resistor 
and see that 1A is available. When the OS is suspended, the PMU manages 
the charge until the battery is charged whereupon it switches off - and 
stays off. If the OS is running, it will cycle back on when the battery 
level falls to 10-20% (reports vary) as the OS can reset and renegotiate 
the charge level. 

If the battery is very low (i.e., the internal fail-safe disconnects 
it), remove it from the phone for 30 seconds or so. This allows the 
fail-safe to reset (this is what I think happens based on my 
observations) so the 100ma can get to the battery, and also reset the 
phone hardware - in particular the GSM modem which is directly connected 
to the battery and is thought to be root cause by Andy Green - possibly 
goes into a wierd state as power drops as well, preventing restart until 
reset. 

The power rail of course drops due to the inrush current much more 
during startup with a low battery than normal, causing one chip (USB I 
think) to detect a dangerously low voltage and issue a shutdown. So you 
cant get the phone to boot until the battery has had a few minutes of 
charge. 

In my case, USB to my laptop or a desktop machine does it. 
Remove/pause/replace battery 
plug into USB for 5-10 minutes 
remove/pause/replug USB cable and normal boot will happen within a few 
seconds. 

The wall charger should work as well, but on my one try it didnt - 
possibly because the u-boot wasnt new enough at the time. 

Recommendation - use a late (latest!) u-boot. 

BillK 



On Tue, 2008-09-30 at 22:13 -0700, Michael Shiloh wrote: 
> > Vince, 
> > When my battery died I plugged my phone into the OpenMoko supplied 
> > charger, started it using NOR boot, leaving it at the boot menu until it 
> > timed out (repeat that twice) then I was about to select boot from the 
> > NOR menu and after a few extra seconds the phone booted. 
> > 
> > -Shawn 
> > 
> 
> I'm confused. I thought that we didn't turn on the charger until we 
> booted into Linux. Am I wrong? Do we charge in u-boot, even at a low rate? 
> 
> Michael 
> 
> _______________________________________________ 
> Openmoko community mailing list 
> community at lists.openmoko.org 
> http://lists.openmoko.org/mailman/listinfo/community 
-- 
William Kenworthy <billk at iinet.net.au> 
Home in Perth! 

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