May I kindly say that 45 minutes to an hour's use from a
BRAND NEW battery seems poor indeed. I would expect at least 1.5 to 2 hours stable charge from a NEW battery of this size, even an inexpensive aftermarket one. I would keep searching for a better deal than that. I sell batteries myself so I'm very interested in this topic

I've found New Old Stock supplies of genuine I.B.M. O.E.M. batteries for the A20, A30, T20, T30, R40, 390, I series 1400, and many others that work wonderfully well after an initial charge overnight. They hold a full charge and honestly I don't notice any major performance deficit between these Old Stock batteries and charge time expected/reported from when they were first newly manufactured years ago. However, I can't say that I have used them for a prolonged period of a year or two and know that they will have the same/almost the same life expectancy as a Li-on battery newly manufactured in 2011 after undergoing many charges/discharges and seeing much usage.
New Old Stock or Used & holding a good charge is the way to go when it comes to batteries for these older IBM laptops, and they certainly do better than 45 minutes to an hour

However, I have not found any large quantities of New Old Stock Thinkpad 600 batteries so far. Therefore I cannot comment on the viability of New Old Stock or used 600 batteries. And I only see a few used, O.E.M. Thinkpad 600 batteries for sale on Ebay "as is" without any mention of how long they last. So you're taking a gamble. I don't know how these Ebay sellers expect you to shell out 20 to 40 bucks for a battery only described as "in good working condition." That's why, whenever I personally sell batteries I time them out carefully or at least use Lenovo Power Manager to check Full Charge versus Design Capacity, and number of cycles. If there are no reliable sources of good quality O.E.M. batteries left for the good old Thinkpad 600 then I guess we have to find a good aftermarket replacement battery with a history of good feedback.
One question: What is this "bad memory problem" you are referring to? Are you saying the original O.E.M. Thinkpad 600 batteries had performance issues and would die prematurely? I think I remember reading something about that somewhere, but I don't recall the specifics. Can anyone elaborate on that issue? One thing I
can say is that most of the Thinkpad 600, 600e or 600x laptops I've purchased had completely dead O.E.M. batteries or O.E.M. batteries holding a modest 10 minute to 30 minute charge.
But if a New Old Stock 600 battery can be trusted to perform, here's a deal for one, Factory sealed that you can jump on:
http://www.ebay.com/itm/IBM-12J2464-THI ... 3a698b6ef2 The seller doesn't have a lot of feedback so proceed at your own risk. However, if you check his Feeback carefully you find that he sold one just like this already and got a Positive:) If it is indeed New Old Stock, factory sealed in the IBM Options box, you may just have to give it a charge for at least 12 hours overnight and may have a great deal on your hands.
Has anyone purchased Thinkpad 600 batteries from this Ebay seller?
http://www.ebay.com/itm/Original-Batter ... 19c7d417d6 He claims Brand New, "genuine, original", with a 1 year warranty. Are these authentic I.B.M.? If so, are they manufactured recently (2010,2011) or New Old Stock from years ago? If they are indeed authentic and genuine IBM batteries then this seems like a good deal and I would certainly go for these versus an aftermarket battery which gives me only 45 minutes to an hour of usage. The seller's feedback on these "genuine, original" batteries sure seems to be good. One question for the experts here: Are there certain manufacturers in China officially commissioned/licensed by IBM/Lenovo to manufacture NEW batteries for the Thinkpad 600 and other older laptops
and put the IBM name on their product? ARE THESE BATTERIES FROM THIS SELLER GENUINE IBM? I really want to know. Someone buy one please, and post photos of it. The
seller's photos show the genuine IBM logo, but I know many Chinese/Hong Kong sellers on Ebay use the original OEM IBM photos but then send you an aftermarket, non-OEM product.
Daniel,
the little YP in NYC
The Best Teacher is a Lifelong Student