Separate charger vs charging battery in Thinkpad ??

[kstuart]

Hello,

Does anyone know specific details about the effectiveness of charging batteries in separate/external IBM Battery Chargers versus charging them in the Thinkpad itself ?

Do they both use the identical charging circuit ?

( At first I thought that a device dedicated only to charging might do a better job... then I occurred to me that, after all, a charger is just a rudimentary computer, and so a much more sophisticated computer, i.e. a laptop, might do a better job. So, I think that only actual engineering knowledge about the devices can answer the question, rather than theory. )

[rkawakami]

Do they both use the identical charging circuit ?

Ken,

I might have a partial answer to your question in about a day or so. I opened up one of my dead 600X batteries yesterday and I'm in the process of taking some pictures and putting up a site. I also have a couple of the external battery chargers and if I get brave enough, I'll try opening that up as well and documenting the innards. For a quick, but possibly wrong answer, I would say that "yes" they use an identical charging circuit. The reason being is that the battery pack contains a fairly complex circuit board which I am assuming for now, is the charging/monitoring system. I've suspected that for quite a while but have never seen any documentation on what's inside the battery pack.

edit: I should have figured somebody else would have already documented the battery pack. This link,

http://www.milnoc.com/TP600Battery/Inside.html

is just about what I was going to do. I found it when searching for one of the part numbers on the circuit board (AN8165NFHP). Since this part of the battery charging system has already been performed, I'll see if I can get to the external battery charger tomorrow (unless someone else has already beaten me to it!).

[rkawakami]

Okay, here's a quick and dirty site showing what's inside the external battery charger (FRU 11J9003):

http://www.rkawakami.net/ibm_600x/battery_charger/

There's more in there than I first imagined. I figured there was just a simple power supply or charging circuit since the battery itself has its own "smarts" via the small PC board mounted within. Since I do not have any schematics on this charger or the laptop, I can only assume that they are similar enough in operation. Which one is "better"? Don't know, but from a purely temperature-based opinion, the external battery charger may be better since the battery will not have the additional heat being generated by an operating laptop, nor is it encased inside a laptop and thus trapping any heat while being charged.

[kocoman]

Has anyone thought of replacing the charging board (ie: from a non-problem battery, like 570..?) to fix the 'balance voltage' problem?

ie: which chip is the buggy one?

AN8165NFHP
BDE3AB
etc?

It seems no one knows about the other chips does beside the EEPROM..

I am trying to find out what pins 7,8,9,10 are, are two (7 and 9) of them monitoring pins? (10 is negative, 8 is positive)
See this picture
img]http://www.milnoc.com/images/li-ion06.JPG[/img]

I am trying to convert the battery pairs from:

3.7,3.7,3.7 (2 per set)
into

11.1, 11.1 (3 per set)

Is it possible?
This will reduce some soldering of 'tabs' because I have some voip li-on backup battery that I can convert directly by soldering their 'wires' instead

[Tõnis]

I often wondered if an external battery charger is even made or available, and seems that it is! What about for my R61? I have two 9-cell batteries and wouldn't mind having a charger for them also. Could someone please provide a link for such a device? TIA,

Tony

[RealBlackStuff]

http://store.jcbarn.com/exbachforble.html

[Tõnis]

Thank you!

Tony

[bill bolton]

Does anyone know specific details about the effectiveness of charging batteries in separate/external IBM Battery Chargers versus charging them in the Thinkpad itself ?

I have an IBM device which charges two T4x batteries externally from a T4x ThinkPad. It's powered from a standard 72W ThinkPad power brick and will do the two batteries sequentially.

I have used it succesfully when at conferences with a T41 and T43, and it works well for charging a battery to 100%.

Do they both use the identical charging circuit ?

The internal charging in later model ThinkPads (later T4x models onwards) allows user setting of charge start thresholds, whereas the external charger I have just charges up to full capacity no matter what, so the approach is clearly not "identical".

Cheers,

Bill B.

[Tõnis]

Do they both use the identical charging circuit ?

The internal charging in later model ThinkPads (later T4x models onwards) allows user setting of charge start thresholds, whereas the external charger I have just charges up to full capacity no matter what, so the approach is clearly not "identical".

Cheers,

Bill B.

But could the batteries themselves be smart enough to remember the thresholds set using the Thinkvatage software (thereby limiting the charge they take from the external charger)? I would like to get one of these chargers, but now I am hesitant, because I fear my batteries could charge in a dumbed-down fashion ...

Tony

[bill bolton]

But could the batteries themselves be smart enough to remember the thresholds set using the Thinkvatage software (thereby limiting the charge they take from the external charger)?

Feel free to grasp at whatever straws you wish!

[Tõnis]

But could the batteries themselves be smart enough to remember the thresholds set using the Thinkvatage software (thereby limiting the charge they take from the external charger)?

Feel free to grasp at whatever straws you wish!

Settled! I will not get one of these chargers.