BL-5C Nokia battery information NA, why?

[Rask Ingemann Lambertsen]

On Fri, May 15, 2009 at 05:03:32PM +0200, Laszlo KREKACS wrote:
> Hi!
> 
> Maybe the wiki is a bit disambiguous, but none of the replacement battery works
> in freerunner.

   Please define "works". Note that you can simulate a non-GTA02 battery
simply by putting a piece of paper or plastic between the middle pad
of the battery and the middle pin of the battery connector.

> That said, the battery in freerunner has a "Coulomb counter", which is
> required by the freerunner.

   Please define "required". Note that you can quite easily try it out
as explained above.

> All the other battery does not contain a coulumb counter (nokia bl-5c,
> 6c, etc), therefore freerunner CAN NOT charge it.

   Please define "CAN NOT charge". Note that you can quite easily try it out
as explained above. Simply put in a battery with middle pad covered and see
if it charges. When you want to check the capacity, just take out the piece
of paper or plastic.

   (If you can read schematics, also note how the coulomb counter is not
connected to the charger circuit.)

> And CANT display the remaining capacity.

   True (sort of - with the 2.6.24 kernel you could at least read the
battery voltage, which gives an indication of the charge level).

> The only way to use this batteries atm, is you charge the battery
> EXTERNALLY (via an another nokia phone or external charger), then you
> put into the freerunner and use it.

   Stop! Just before, you said: "none of the replacement battery works
in freerunner." 

> However you will not have any indication about the remaining capacity.

   True (sort of - with the 2.6.24 kernel you could at least read the
battery voltage, which gives an indication of the charge level).

> That said, if somebody write a correct driver it can be charged this
> type of batteries too. The problem with it, is the exact specification of
> the battery is not available, and if you charge incorrectly it can even
> explode.

   Already true. External power permitting, the Freerunner will try to
charge whatever battery you insert to 4.15 V with a 1000 mA limit.

> So writing a correct driver requires many trial-and-error, and the possibility
> to destroy the battery and the freerunner too.
> Because you need to estimate how much you already charged the battery
> (the coulomb counter says exactly how many charges it took), and the
> remaining battery indicator would be just an approximation.
> (like the 3-4 bar on the mobile phone)

   Please explain why you need to know how much you already charged the
battery. Hint: Search for "charging procedure" at
<URL:http://en.wikipedia.org/wiki/Lithium-ion_battery>. See also the
specifications for the Sanyo UF653450S as used in the Freerunner:
http://battery.sanyo.com/en/spec/ion/UF653450S.pdf

   Btw, the coulomb counter doesn't know how much charge is lost to internal
leakage in the battery.

> It is just a speculation, but imho writing this driver is not as
> difficult as it seems at the first look.

   True. In particular, there is already a "GTA01 dumb battery" driver.

> If somebody spy how the nokia phone charges its
> battery, we could replicate the
> process. We should simply monitor the voltage and the current of the battery.
> Needs some simple circuit(couple of wires and a soldering iron, and
> proper multimeter).

   Sure, but you'll find no surprices there.

> Correct me if Im wrong.

   In this particular case, it's easier to point out the things you're right
about. :-(

-- 
Rask Ingemann Lambertsen
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