February 22, 2004.

Marton A. submitted parts information for chip C on the circuit board.  It's a CMOS EEPROM  chip readable with the Elnec Smartprog EEPROM programmer.

May 5, 2002.

The following text and images are from a contributor who opened one of his battery packs which couldn't hold a charge anymore.  The information is invaluable in our ongoing research to resolve the case of the dying battery packs.  As a precautionary measure, I decided not to reveal his true identity so that IBM doesn't attempt to void any of his warranties.  I also wiped out any identifiable serial numbers from the original images.

The following information is supplied by the contributor with only a few very minor changes and corrections applied to the text.  I would like to thank our contributor once again for this invaluable information.

Hi François,

The battery I disassembled was a completely ruined one, so don’t take yours apart!  The battery on the left is my good one, remember 100% ->35% in half an hour, then 0% for 30 mins+???

I pointlessly removed the stickers from the top (yellow) and bottom (black), there are no hidden screws or anything exciting, just some holes that don’t appear to serve a purpose, i.e. no test pads exposed.

Using a knife, I carefully applied pressure around the seams to free the glue.  It’s basically a clam-shell type of container that is glued together.  "Dave, what are you doing Dave!" – HAL, lol!

You’ll notice the bump on the top of the battery with the IBM logo.  This houses the so called intelligence circuitry.

And indeed all the batteries are manufactured by Panasonic.

The circuit board.

I’ve tried to map out the circuit on the film with numbers for you.  Nice to know where those pins go to!

There are 8 solder points that go to the circuit board.  Like I said in my mail it’s a lot more complex than I imagined.  Notice the battery protector and thermister.

(1) Full product number: AKM93C45AF.  Data sheet: dam01e02.pdf .  Thanks goes to Marton A. for the info.

The underside of the PCB is just populated with resistors and capacitors.

Here are some side shots of the batteries so you can see how they connect to the film.

This is my best side!!

Looks like some futuristic moon rover!

This battery by the way was totally dead, 0 volts from the pins. It would not even take a charge (the amber light flashes even with the mains connected).

The Klixon circuit protector appears okay.  It measured 0 ohms indicating it would pass current.  The thermister registered 9.86K Ohms at room temperature, and declines when heat is applied.  However, the batteries appear to be completely exhausted.  I’m not surprised though if the integral monitor will not allow them to charge!

Well that’s about it.  I’m off to bed now, good luck with your research.