CMOS battery compatibility

[Norway Pad]

Hello all

Almost at the same time, the CMOS batteries in two of my T42s went dead. I started looking on eBay for new ones for the T4x, but the prices are very varying. I suspect I might want to avoid the cheapest China ones, at which point I'm looking into at least $10 pr. battery.

So my question is: Which models of newer Thinkpads have compatible CMOS batteries? It's impossible to see from the auctions. Some of them claim to be compatible across many model ranges, while other ones are listed as only compatible to one single range. I would, however, suspect that the T4x ones might be compatible to the newer ones, like T6x, Z6x and some T4xx/T5xx. From what I can see, the batteries for these newer ones seems to be cheaper. I would also like to keep some in spare, as I suspect my T43s are next in line for having their CMOS batteries die.

While we're at it, does anybody know the compatibility for the older ones, like the T30, T2x, G40 and 600/770/560? Even though I have already changed the CMOS batteries in some of the older ones, I suspect I will have batteries die from time to time. So I would like to keep some spare batteries for the older ones too, and hopefully I can keep a couple of batteries who fit more than just one specific model.

[rkawakami]

This may not totally answer your questions, but it might be a good starting point:

http://forum.thinkpads.com/viewtopic.php?f=18&t=90787

In the past I've consulted the appropriate HMMs when trying to figure out if a CMOS battery could be used in more than one system.

[Norway Pad]

Thanks for this one, this thread didn't show up when I searched today. Some useful hints there.

I would still like to know if anyone have had luck using the a T6x CMOS battery in a T4x, or opposite. That would make my purchase easier and cheaper. For the older ones machines, I might just read the HMMs, buy some batteries and test them.

[rkawakami]

Here's the result of a quick scan I made of the HMMs I keep on my A31p system here at work:

Battery
FRU	System

12J1695	560X, 560Z

02K6502	600, 600E, 600X

02K6572	570, 570e, A20m, A20p, A21e, A21m, A21p,
	A22e, A22m, A22p, A30, A30p, A31, A31p,
	T20, T21, T22, T23, T30, (T40, T40p, T41, T41p, T42, T42p 15"),
	T43, T60, T60p, T61, R61, R61i, T500, W500

92P0991	R40

02K7078	R50, R50e, R50p, R51, R51e, R52, R60,
	T410, T410i, T420, T420i, T510, W510,
	X30, X31, X32, X220, X220i, X200t, X200it

04W3253	T420s, T420si

92P0986	(T40, T40p, T41, T41p, T42, T42p 14"), T400, R400

02K6715	X20, X21, X22, X23, X24

92P1004	X40, X41, X41t

92P1210	X60, X60s, X60t, X61, X61s, X61t,
	X200, X200s, X200si, X201, X201i, X201s

42T4524	X300, X301

92P1161	Z60t, Z61e, Z61m, Z61p, Z61t

My suspicion is that the differences between some of them is in the length of the wires. In other words, the 14" and 15" T4x CMOS batteries probably have the same type of connector and orientation of polarity, but only differ in how long the wires are. I don't have any 15" T4x system to compare so this is just a guess.

[RealBlackStuff]

The same one can work at least in all T2x, T30, T4x, R5x, T6x, R6x.

[Norway Pad]

Thanks a lot! That's what I needed to know.

I have a dead T60 in the storage in my basement, so after I wrote the last post, I realized that I can pull the CMOS battery out of it and compare it to the dead ones from the T42s. That can also give a hint about the cable length. This afternoon I also found dead T30 and dead 600 CMOS batteries in one of my parts boxes. I was sure I threw them away, but I didn't, and I was at one point smart enough to make notes on them what computer they came from. So I will compare all these connectors and post the result here for reference. As they are all dead, I can't measure any voltage, so this is all based on the assumption that the voltage is the same across the entire range.

[rkawakami]

I believe that from at least the 600-series systems, the CMOS (backup) battery has been a 3V lithium coin battery (CR2025 or CR2032; CR2016 too??). The dead batteries will still be useful as you should be able to determine the polarity of the connector by the red (+) and black (-) wires.

[danikayser84]

Going back even further, the early 560 (up to the 560E), early 380 (up to 380ED), and all 390 series use a standard CR1220 battery (which can be bought at any drug store, supermarket, Best Buy etc.), all 770 series (770E/770X/770Z) use a standard CR2025 which can also be bought just about anywhere

My 380XD and 380Z use a 02K6498 battery, which is a CR2330 in shrink wrap, too; AFAIK I haven't seen the 02K6498 used in any others?

[Norway Pad]

..early 380 (up to 380ED), and all 390 series use a standard CR1220 battery (which can be bought at any drug store, supermarket, Best Buy etc.), all 770 series (770E/770X/770Z) use a standard CR2025 which can also be bought just about anywhere

That's correct. As I have these laptops on my shelf, decided to pop open the ones where the CMOS battery is easy accessible. In the 380ED, 390X, 770Z the batteries danikayser84 lists were indeed the batteries I found inside. In my 560Z and T23, there was a wrapped one, a CR2032 / IBM P/N 02K6541. Same in both. In the G40 I found a 1220 battery.

At the same time I dug out the old batteries I had lying in the box, and took a picture of them all lined up. https://lh3.googleusercontent.com/Wj-r8 ... 00-h800-no

From the top we see:

600 - Different plug, wrapper says CR2025 / IBM P/N 02K6486
T30 - Same plug as the 2 following batteries. CR2032 / IBM P/N 02K6541
T42 - CR2032 / IBM P/N 02K6541
T60 - CR2032 / IBM P/N 08K8050

So we can see that the T30 and T42 came with the exact same battery, which also was found in the 560Z and the T23. I have owned the T30 and T42 since 2008 and 2009, so I suspect these are the batteries that were installed by the factory. For the T60 battery, the part number is different, but the plug and the battery inside is the same, and the length of the all the wires are the same. So off to eBay to buy some batteries!

[precip9]

My suspicion is that the differences between some of them is in the length of the wires. In other words, the 14" and 15" T4x CMOS batteries probably have the same type of connector and orientation of polarity, but only differ in how long the wires are. I don't have any 15" T4x system to compare so this is just a guess.

My suspicion also. All lithium coin cells have exactly the same voltage, 3.6V. So any difference is in the leads.

[Norway Pad]

The battery that fits all units from the 560Z and up, and the T60 battery has the same length of the wires. The only one that differs is the 600 one, which has slightly longer wires. So it's no apparent reason why the T60 one has a different part number. Except from the fact that it has a piece of double sided tape under it.

[RealBlackStuff]

That's just another money-making racket, but one that does make sense.
CMOS batteries last on average about 5 years.
Nobody would order one with a P/N or FRU from 20 years ago, the battery might be just as old!
So they created a new P/N or FRU for each new model/series/generation.
That way you should get a "fresh" battery, unless it's another fake...

[Saucey]

I'd like to chime in and say I swapped a T420 battery from a X61 sucessfully.
Perhaps the T430 uses the same, I didn't take note of the T410 when I had it but I believe it could of worked as well.

[danikayser84]

Sorry to bump an old thread, but I'd like to point out a small word of warning on ThinkPad G40 and G41 models: the CMOS battery is actually a rechargeable ML1220 (lithium ion) and not a standard CR1220 (like in the 365X/XD, 560/E, 380D/ED and 390s)... I discovered this when I recently received a G40 for parts (I didn't think anything of it because my G41 came with a dead CR1220 and replaced it with one initially), be careful not to make the mistake of using a CR1220 instead of the correct ML1220

[rkawakami]

Well it's not surprising to me that I don't know that; I've never even seen a G4x system in person. A quick check of the G4x HMM says the FRU is 92P0992.

Putting in a silver oxide or alkaline (i.e., non-rechargeable) battery into a slot which assumes you're using a rechargeable battery is not good. At best, I can see a shortened lifespan of the battery. Worse case, it could leak or explode.

[Norway Pad]

Wow, thanks. Good to know.

I have a G40, and I think I might have replaced the CMOS battery there at one point. But I have had no issues, so I might confuse this with one of my other 20+ legacy systems. I better open it up and check what's in there..

[thinkpadcollection]

600 series cmos battery white connector is longer and narrower than stubby and little more wider common connector that majority of thinkpads uses.

Cheers, thinkpadcollection

[rkawakami]

As I referenced in my first response to this topic...

http://www.kawakami-ca.com/images/02k65 ... 2k6715.jpg (37KB image of three CMOS batteries)