New Original Genuine IBM Lenovo Thinkpad Battery 33++ 43R2499 T400 R400 T61 R61 9 Cell Battery

New Genuine IBM Lenovo ThinkPad Battery 33++ (43R2499) 9-Cell Battery. For T61, R61, R61i, R400, T400 14-inch Wide Screen Models Only. (Caution**: Not for T61, R61 Standard Screen Models).

Owner Reviews, Ratings, Comments and Criticism
I own two Lenovo laptops. A T400 and a T510. Recently, the original 4 cell battery on my T400 started to loose charge very rapidly (the battery is now 3 years old) and so I decided to go ahead and order a 9-cell battery for my T400 to replace the factory original 4 cell battery. I decided to spring for the 9-cell one so I could get around 4/5 hours of use time on the road without having to re-charge. This expectation was based on the use i get out of the factory original 9-cell battery I have on my T510.Since I already use a 9-cell battery with my T510, size of this battery was not an issue. I knew what I was getting into size wise.This same battery was for $179 on Lenovo and therefore I ordered the battery from this seller on Amazon at around $90. The ordering was hassle free and the package was delivered quickly by the seller (3 stars are for this).The battery is working fine with my T400. The laptop recognizes the battery. It does not complain. So far so good. Currently, on a full charge, the power manager indicates available time of 5 hrs 45 mins when I use my highly power optimized profile. However, I don't have enough data to talk about the use time under various conditions yet (will update this later after using the battery more).The reason I give this product only 3 stars is due to the 'manufacture date' on the battery. Based on the manufacture date, the battery is 19 months old as of the date it reached me and I am very disappointed because of that. From what i understand about battery chemistry, Li Ion batteries start losing their capacity to hold charge as soon as they leave the factory (even without any use, check this link http://electronics.howstuffworks.com/everyday-tech/lithium-ion-battery2.htm). Although the actual capacity degradation will vary from battery to battery, as a rule of thumb a Li Ion battery will loose about 20% of its capacity to hold charge every year and they seem to have a total life of about 3 years whether you use it or not. So, thinking in terms of the average values, this battery has already lost about 30% of the total capacity and 50% of life. This brings me to the pricing of this product. Although the price is significantly lower than the pricing on the manufacturer website, you only get what you pay for. Half the life for approximately half the price. In conclusion, the next time around, I will highly consider purchasing a new battery from the manufacturer (which tends to have a recent date of manufacture in my experience) so i can get the full 3 to 3.5 years of usage. Although the initial price is higher, the usage time to price ratio is slightly higher when purchasing straight from the manufacturer. The only reason I would buy a laptop battery from a third party seller again is if I do not plan to keep the laptop for more than 2 years.