R40 replacement CMOS battery

[VIBM]

I got an R40 type2897 and it needs a new CMOS battery(always needing to set date and time page on bootup).
I am getting conflicting information when looking up battery replacements on ebay and amazon.
I read in a previous post, that a standard TP 3v lithium battery can be used if wires are reversed, but I would rather buy a "ready to go" battery.

Is it correct that the CR2032 will NOT work in R40?(I read in one amazon ad, that it is not compatible for R40).

For example this ad only lists R40, but no part reference number:
http://www.ebay.com/itm/NEW-IBM-THINKPA ... 5d36b745c1

The correct battery part# is 92po991, so should the ad also list this number?
I just don't want to get the wrong battery with wrong polarity, and damage my laptop.

I would appreciate any help for clarification.

[rkawakami]

You are correct about the part number. The R40 Hardware Maintenance Manual says that the CMOS battery is 92P0991. A search at Lenovo Support appears to say that FRU is only referenced for the R40/R40e systems.

IBM used several different wiring and connector formats for these backup batteries. It may indeed be possible to use a battery (as-is) from another system or "reverse" the battery leads on the connector of an "in-compatible" one: http://forum.thinkpads.com/viewtopic.php?f=18&t=90804

However, I would be very careful that you make sure that the connector and polarity of the wires is the same as what you are removing from the R40 before plugging it in. A regular CR2032 battery may not work in that it would be thicker than the original battery, which is probably a CR2025.

The eBay listing you referenced appears to show a battery with a connector that is compatible with an R40 but the wiring seems reversed if RBS is correct about the R40 in the thread I mentioned above. It also says it will work in R5x systems (which I don't know is true or not as my R50 is at home; I'll see if I can find it tonight to confirm).

In short, I'd only buy a battery from an eBay seller that absolutely guarantees that battery is compatible with the R40 AND you are prepared to ship it back (at your cost probably) if it isn't. The best thing you can do before buying it is to take a close-up picture of the connector, showing how the black and red wires are arranged with respect to any visible metal contacts and send it to the seller.

[VIBM]

Thank you very much for all the information. I will follow your advice, and open the laptop, and take some pictures. I've had other thinkpads, but accessing the CMOS battery on this particular model, looks like a real pain.

[Wemzy]

Hello

im the newest kid on the block here, i tried replacing my cmos battery, and took it out, and i can confirm its a 2032 battery

problem is that i didnt photograph the terminals, i sent it with a new battery to be soldered on instead, and they returned it in pieces.

so i brought a new one on amazon (Yes! a cheap chinese knockoff with a plastic bracket), The bracket was no good for the R40e so i tossed it.

i read the amazon posts and someone said it didnt fit, i tried it and it did fit, and posted that it does fit, someone then replied that using it as it will fry my CMOS EPROMs, so i have removed it, thankfully my IBM R40e still works, but im worried it may be a prank (PS i didnt use it with the new battery, due to a bad PSU)

Help! i need a photo of the terminals, if someone (VIMB) still has it.

Thanks

[RealBlackStuff]

Ray, your link goes to a wrong post.
The correct CMOS-battery link is: http://forum.thinkpads.com/viewtopic.php?f=18&t=90787
And in an R40 you can use either the depicted black one (C), or the common yellow CMOS battery (A), if you reverse the wiring in the white plug, so it matches (C).

[rkawakami]

Hmmm.. thanks for the correction. I'm pretty sure that it was correct when I posted it last year.