Battery ID chip - help needed

Laszlo KREKACS laszlo.krekacs.list at
Wed Jun 10 23:24:04 CEST 2009

On Wed, Jun 10, 2009 at 11:04 PM, Christian
Gagneraud<cgagneraud at> wrote:
> According to the schematics of the FR, the ID line of the battery is
> not connected to anything (R1769 is marked NC). I checked my FR rev A6
> (from your shop Christoph!;)), and this resistor is not populated.
> So it means the ID line of the battery is definitely not used.
> Now I'm not saying it is safe to use whatever battery, i'm just saying
> that the power management chip (the PCF 50633) is not able to read any
> information out of the battery you fit in your FR (like battery ID,
> serial number, etc...).

I dont think it is true. Openmoko's battery is "special", it includes a coulumb
counter. And the battery indicator relies on it.
So inserting a nokia BL-5C battery is not complete solution. (because it lacks
the coulomb counter), and freerunner cant charge it (currently) and cant
display the remaining capacity.

The best person to ask are jOERG or Werner. They usually hangs on
#openmoko-cdevel and are very helpful people.

> The FR is designed/programmed to charge at 500mA max. It should be

It is not true either.

1. Freerunner identifies the charger with a "magic" 47kOhm resistance
between D+ and D- line.
If the resistance is present it charges with 1000mA.

2. If the usb enumeration was successful it charges with 500mA (so
connecting to a computer charges with 500mA).

3. If none of the above happens, it defaults to 100mA.


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