(NAND) boot problems with empty batteries ?

[Evgeny Ginzburg]

Harald Koenig wrote:
> Hi,
> 
> when my gta02v5 battery is completely empty I have two problems booting again at all:
> 
> 1) NAND u-boot does not work:
> 
> after connecting AC charger I can start only NOR boot (aux button first),
> but the NAND boot (no aux button, only pwr button for 10+ seconds just
> does nothing, the aux button doesn't blink then either).
> 
> removing power and battery for some 10 seconds doesn't help.
> 
> just charging 10 minutes (using AC charger) before trying [nand] boot doesn't help right now either.
> 
> update (I write this email because right now I'm that "out of power mode again":-(
> 
> after 10+ minutes connection to AC charger (still powered off) I can't even 
> get into the NOR boot anymore.   
> I removed the battery and AC, reconnected both and NOR boot came up.  
> here I selected "power off" and tried to do a regular NAND boot (no aux) -- doesn't react.
> now NOR boot doesn't work either.
> after some waiting (1 min?) NOR boot comes up again, now I selected "reboot" 
> (is this supposed to re-boot the nand uboot?).  the screen got white for ~2 seconds,
> than black again and that's it:-(
> 
> what's going wrong here ??
> 
> 
> 2) boot process crashes (switches off) with usb power from notebook
> 
> if I connect the FR to my notebook (Lenovo T61p) for power and once I manage to boot,
> the boot just crashes after a while (1-2+ minutes), I only have a black screen then
> and all I can do to boot again (long pwr on).  usually in this situation all futher 
> tries to boot won't come up either.
> 
> I'm not sure if these crashes might be triggered by the notebook having some USB problems
> ("device not accepting address ...") and thus disabling usb power for that port
> ("port 2 disabled by hub (EMI?), re-enabling...") or if that hub-disabling is only
> a result of the FR already being crashed or switched off during boot.
> 
> 
> 
> solution in this case: I removed the empty battery, replaced it with the battery 
> of my "real" (nokia) phone (nokia). then boot works, and while FR is running and
> connected to the notebook I swap batteries again and charge the empty FR battery.
> 
> I had this situation(2) at least 3-4 times before using various uboot/kernel/distro versions,
> I only started using the AC charger yesterday and realized, that it supplies 
> much higher current and charging goes much faster (almost a fator 3 in charging rate!)
> 
> 
> 
> 
> are these known problems ?
> how can I get the FR up with empty batteries, how to charge an empty battery ?
> 
> 
> thanks for any hint or comment,
> 
> Harald
http://wiki.openmoko.org/wiki/Freerunner_Hardware_Issues#PMU/Charger Issue