Thinkpads Forum

Hello, ThinkPadders,
I've recently been modding up my 600X (more RAM, internal WiFi/Bluetooth, new battery) and as I don't use an optical drive much I'm going to be purchasing an UltraSlimBay battery for the low, low price of $8.
Now, due to the bargain basement price, I'm assuming that the cells are mostly if not completely shot and as such I'm wondering if it's possible to replace the cells with working equivalents, as is possible with many other Li-Ion batteries (or if possible to replace with NiCad tech for better shelf life).

Also, I have an Eee PC battery that outputs 10.8 volts and gets 5 hours of run time, same voltage as the ThinkPad takes in. Any chance I could use it as an emergency battery?

I am in the same boat, but with thinkpad T42's and the Ultrabay slim. You can communicate with me via the email, gillies@ece.ubc.ca. I am looking to change out the cells in my ultrabay slim batteries, for new ones. Alternately, I just found a website that talks about restoring NimH batteries, and it also asserts that most dead battery packs have just 1 or two bad cells, therefore, with 2 or more dead packs you should be able to make 1 half-decent battery pack :

http://www.batteryuniversity.com/learn/ ... _batteries

I have found several web pages where people disassembled a 9-cell thinkpad battery, changing out the 18650 cells for new ones. That can make a 9-cell battery pack work like-new. I have been unable to find ANY websites where people did something similar for Ultrabay batteries.

When changing out the main battery pack cells, you need to check the candlepower forums and buy high-quality 18650 Li-Ion cells (T4x main packs). High-quality cells are not cheap. Nearly all of the cheap cells with high mAh ratings are just "Liar Batteries". The total capacity does not matter as much as the number of charge/discharge cycles that the cells support. Most cells that are advertised as "high capacity", fail to store that high capacity after just a few cycles, if they EVER reach that capacity in the first place!

Higher-capacity cells tend to have far fewer charge/discharge cycles. This is why the Toyota Prius keeps runs a duty cycle from 40% charged to 60% charge, and stays inside that range. They trade off 80% of the capacity, for longer life! It is far better to have a cell with 20% less capacity and 200% more charge/discharge cycles (which means the battery pack will, overall, last 140% longer with lower-capacity cells.) For NimH cells, Sanyo Eneloop is the charge/discharge champion ~ they have 20% less capacity than a typical NimH cell (2000 mAh vs. 2500 mAh), and 200% more charge/discharge cycles (1500 vs. 500), for a total lifetime that is 140% longer than other cells.)