Nokia Battery pinout

Yes, your multimeter leads.

OK Let's label the pinouts as ABCD. The battery is fully charged. So I
measure just over 4V between A and D. Between A and C I measure just under
4V.  Could this be a reverse protection diode in circuit? Could it be a
thermal switch with near 0 resistance? I could speculate, but I dunno.
I do not measure anything between A and B. Can I be sure that there is
nothing connected to B? Again I am none the wiser.

As the battery is very popular I would assume that someone out there has
already done the hard work for me. That's why I ask whether anyone has come
across a website with the internal details.

Forget the battery, why not check the charger you already have.

That would be the phone wouldn't it? :-)

"Heywood Jablome">



 ** The battery contacts are A & D.

  Bet the polarity is marked in the plastic nearby as well.





 **  The battery  PLUS a series thermistor.





 ** No.





 **  That's for sure.




** Now switch your multi-meter to ohms and probe between the contacts that
showed NO voltage reading

 It will maybe read something like 50 ohms to 50 kohms.




...........  Phil

Two outside ones are + and - (marked on the label side). The other two
are for battery id (you can get BMC-3 which is NiMH in the same housing,
it works with the same phones). I've read some details about middle
terminals some months ago and don't remember very well. I think there is
a resistor between middle terminals with different value for BLC-2 and
BMC-3.

My own research - BLC-2 seems to have ~122 k resistor between the middle
terminals and nothing else while BMC-3 has ~39 k resistor between middle
terminals and a diode(?) between + and closest terminal - 0.37V one way
one no current other way.

I'll try to dig out the original info.

Tom

he'd be better off with the ni-mh battery in my opinion, lithium
batteries are very picky about how they are charged and likely to go
bang in a bad way if handled wrong, however, you could use an old 3310
or equiv' to hold and charge the battery and just tap from it with some
wire.

highly recommend using the ni-mh version if you are going to charge with
simple stuff.

charging
hack" I


Thanks Tom. I'll investigate that and see what resistance I get. What I am
also interested in is the charge rate, maximum allowed discharge rate and
other specs, so if there is a reasonably reputable web site with these
figures, that would be nice.

I am quite aware of the dangers of incorrectly charging/discharging lithium
batteries. The charge circuit that I plan to build within my device will be
microprocessor controlled with fail safes. Unfortunately the space
requirement does not allow for a mobile phone to be inside the enclosure.

The 2 center terminals 'should' be a temp sensor for use with a delta time/delta
temp charging system.  Easy way to tell is if it changes when it's warmed up in
the hands or cooled in the fridge.

I know temperature change is often used for detecting end of charge for
NiCads, but is it also used for LiIon?

"Poxy"




**  If a sealed battery is fed with a continuous supply electrical energy
AFTER its charging reaction has been completed -  what do you expect would
happen to it  ???

 Convert the energy into mass  - maybe ???




.........   Phil

You are right - the energy has to go somewhere - obviously in increasing
mass...  But in my admittedly limited experience with lithium polymer
batteries, my charger doesn't use temperature sensing. I'm wondering whether
temperature change is customarily used in consumer devices like mobile
phones.

In my case, the charger tapers the charge current, which I assume means some
kind of constant-voltage charge.

"Poxy"




 **   Whooosh ...............


 BTW

Batteries are  CHEMICAL  machines  -  not electronic components..

They are products of the CHEMICAL engineering industry.

Very bloody secretive.

Very bloody weird stuff.

Full of outrageous scams.

See my contributions to EA magazine re: the great  DSE  Ni-Cd fraud .





.......  Phil

NO!

"budgie"




**  The topic deserves more than one word and there are plenty on the net:


Eg    http://www.powerstream.com/li.htm




..........  Phil

It may not be used for charging but I have 3 Nokia batteries here (BMC-3 & 2 x
BLD-3) and the readings on the center contacts change predictably according to
temperature.  It could be a safety issue as my owners manual mentions the phone
may no work if it is hot (eg, left in a car).

In any case the center contacts are definately connected to a temperature
sensing device.

Temperature is used in Li-Ion charging as a "qualifying" parameter only, not as
an end-of-charge indicator.  The charge regime used almost exclusively is
current-limited constant voltage.  After transition from CL to CV, charge is
usually terminated when the current has tapered off to a pre-ordained level like
10% of the CL value.

Unlike NiXX chemistries, Li-on and Li-Poly cells do not exhibit any sudden
change in terminal characteristics as they approach "full charge", and they
certainly DON'T generate any significant heat or exhibit any significant temp
rise when charged correctly.

Most nokia's equipped with "Net Monitor" hidden menus are able to display a
"temp" screen, which I believe is the reading from the batery module..

i found that on the blb2 batt is the two midde tabs tell the phone, the
batt power levels and when to turn the phone off when the batt gets too
low.to save the batt from harm.if your phone shows one bar left then
bridge the two middle contact with tinfoil while in your phone then it
will show "full power" and work for some time (good tip if your stuck
somewhere with a flat batt).there is an unbeilveable amound of
electronics for this inside the battery.there is a temp device inside
but nothing to do with the 4 contacts it simply disconnects the minus
connection from the terminal,(which looks like it should be the plus).