Three months ago I bought a unused battery, sealed in the box, for my X61s, from the eBay seller "computeraccess1997" for a very good price. The battery was genuine Lenovo - but the Lenovo Power Manager reported that it had been manufactured in 2006. The seller offered a partial refund, which I accepted.

I knew that batteries don't age well, and I expected this one to fail quickly. I was right. It worked well for about a month, and then the Power Manager reported that it had failed. So this wasn't exactly a bargain.

If you order a battery from "computeraccess1997" you may be disappointed by what you get.

Thanks Edward for the information. I have not looked on Ebay for Lenovo batteries since just resently I saw a battery for sale by a forum member. So, I am buying the unit, which the member listed the battery specifications (how much charge it was designed for, how much it can hold) for the unit and I have faith in the member on a personal level that he is an honest person from the emails we have exchanged.

John

Thanks for the info.

However I want to note that in theory, anyone could sell a product like that in good faith not realizing that such batteries sometimes have a "sell by date" like milk or produce.

I've bought what appear to be brand-new/sealed genuine Lenovo batteries from ebay sellers before, which worked fine for me. Though it's hard to know whether they are working 100% "as new" without some controlled testing using lots of samples side-by-side.

I would be surprised if there wasn't some sort of date code on the white Lenovo label, though it might be encoded in some way. Knowing that before buying would help a lot. (Of course if it's a counterfeit product, they could print anything they wanted on there)

I couldn't find a human-readable date code on the batteries. I should have been warned by the fact that the batteries weren't in a Lenovo box. I remember that Lenovo's battery boxes have labels with the date of manufacturing on them; I'm not sure that's still true. But now I won't buy a Lenovo battery that isn't in a sealed box.

Well I couldn't find any Lenovo battery boxes around here at the moment, but I did have 2 easily-accessible boxes from other IBM/Lenovo products.

On the white labels:

IBM AC adapter from 2004: clearly-printed manufacture date, in "dumb old 2-digit year USA style", ie: MM/DD/YY

Lenovo Serial Ultrabay Slim BluRay MultiDrive II - clearly-printed manufacture date in ISO format, ie: YYYY-MM-DD

Hmm, am I the only one to automatically assume "New old stock" when seeing something "New" related to past-generation ThinkPads on eBay?

FWIW, I found in this thread, a link to an IBM/Lenovo document that enumerates part labeling standards here. (PDF)

The label layout specifies a datecode format, one of which is human-readable and one of which is encoded in the barcode/serial number, and readable using an app called "i2 eXplore" from a supply-chain management vendor which after a series of acquisitions, is called JDA. LINK

Looking at a 6-cell T400 battery here, I believe the first 3 characters on the left are static ("11S"), the next section looks like the part number (in this case "42T5226" - actually that seems to be the "assembly P/N") and the rest of it include the actual S/N and the part where the manufacturing date is embedded. (In the case of the one I have, that section is "Z1ZFC78B16K1")

Looking in more detail at that PDF file linked above, it appears that the portion of the S/N that is the manufacturing date is the "8B1" part. (The last 6 chars of the S/N are apparently the manufacturing date/lot number)

Which, if I've got this right, would translate to "2008-11-01". (All digits are in hex, 8 is the year after 2000, B is hex notation for "11", and 1 is the day.)