TP 770 Battery refurbishment / reassembly

[Peter]

hi,

i´ve heard of people making a working battery out of two or three "dead" ones. they took the batteries apart, kind of measured the single cells and soldered the good ones (or at least the best ones) together again.

i have two "dead" batteries here and want to try that on my own. does anyone have experience with that?

soldering is not the problem but i dont have a clue how to find the right cells? how should i measure them???

peter

[Bruce Guttman]

I tried the same thing with little success.

To find the "good" cells you should remove them from the flex circuit and test them individually. You will probably find anywhere from 3 to 9 bad cells in the pack. Naturally, 9 bad cells means 0 good ones ...

In order to get good contact, you would need to reweld the good cells back into the flex array. I was unable to get any cells to solder properly. Some folks have had some success with tight bands on 600-series machines.

One other failure to report. I had a pack where all 9 cells checked out good, but it refused to charge. I tried putting the logic from another pack on it, but it still wouldn't run.

AJ Albritton now has all the cells; maybe he can enlighen us on how it worked.

Hope this helps

[Peter]

but how do i test the cells? which tool do i need for that? that is my main problem- never done anything like that before...

[Bruce Guttman]

All you need to test the cells is a good voltmeter.

If you want to try recharging them without using the laptop, you need DC power supply that can be adjusted to 3-4.2 volts.

Hope this helps.