date and GPS related questions

Fernando Martins fernando at
Sun Mar 15 19:26:55 CET 2009

Joerg Reisenweber wrote:
> Am So  15. März 2009 schrieb Fernando Martins:
>> Daniel, many thanks for your replies, please see below.
>> Daniel Willmann wrote:
>>> Hello,
>>> On Thu, 12 Mar 2009 22:19:05 +0100
>>> Fernando Martins <fernando at> wrote:
>>> there is a backup battery, but in my experience it only takes a couple
>>> hours without battery until the time is lost again.
>> I never leave the battery out, I only take it out to reboot after a crash.
>> But now I wonder: usually I keep the phone switched off during the 
>> night, and since I use it rarely, sometimes I forget it switched off at 
>> home. Is it the case that, when FR is switched off, the main battery 
>> does not feed the backup battery? (yeah it sounds weird, the main 
>> battery would become the backup of the backup battery).
> From PCF50633 PMU datasheet it seems backup bat isn't used as long as main 
> battery is supplying sufficient voltage, no matter whether phone switched off 
> or not.
> So backup bat is the backup for main bat, not vice versa ;-)
> /j

Uff, I was getting all confused with these batteries back and forth :-)

I never let the main battery drain fully, so something else has caused 
the date to reset.

BTW, I was also curious whether the backup battery recharge itself, and 
from the datasheet above it seems to be the case.

I still remember the old times where I had to replace batteries in PC 
motherboards. Nowadays motherboards dye before the battery :-)


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