T21 Battery

[jimp39]

Just received a "new" battery from ebay. When it is installed the battery light keeps 'flashing orange". Is the battery no use or is it me????

[dickchailey]

Flat and may be duff. Check its connected OK and leave for a couple of hours - it may recover and charge.
If the thinkpad can "see" the battery you can check its history in Thinkpad config or the power manangment utility. Will tell you the made date, number of charge cycles etc.

[joester]

What I've found is that the individual charge level of the cells can be different between each pair (there are 3 pairs in a normal battery). If the difference is too great (Guessing at a half volt?) the battery is deemed bad by the laptop circuitry. Sometimes the battery will stabilize while plugged in and "recover" as was mentioned.
Another alternative is to open up the battery and charge the cells to read all the same voltage.
(I cannot express enough how dangerous this part is, should you decide to attempt it. You absolutley DO NOT want to short out the cells.)
Then, providing the charge control board is good, the battery will operate normally. If it stops working after that, then the battery needs to have the cells replaced.
-----WARNING-----
Messing around with Lithium Ion cells is not advised to the average home repair person. Lithium Ion cells are particularly nasty when shorted. If the case of a battery cell is breached, the liquid inside it is set aflame by the spark. The flame grows as the cell heats forcing more liquid out to burn until it basically burns itself out. I really DO NOT ADVISE the repair of these type cells at home. Specific precautions must be made to safely handle these batteries. That's why it's so hard to locate and purchase them.

Read more here.

Joe