Guys,

I have a Lipo that got damaged after a crash. One side of the pack is swollen while the other is not. When I connect to a balancer-charger, I cannot get it to charge or discharge. When I check the battery voltage at the balancer port, I get the pack voltage as 3.98, 4.29, 8.55. The voltmeter is not very accurate, but is sufficient to indicate that there is very little potential difference in the 2nd cell. This indicates that the 2nd cell may have been damaged or may be just a case of broken contact. I think it is the later as the cell otherwise looks decent.

So the question is how to go about repairing the same - if that is possible at all.

pankaj

Buy new ones. They are cheap. once I tried repairing it and extracting the cell. Its not worth it. Just you will waste your time.
If you still insist on repairing. Discharge them to 3.2 volts per cell and then dare bringing the soldering gun near.

Here are the threads where I tried to fix my Lipo.

http://www.wattflyer.com/forums/showthread.php?t=52063

http://www.rcgroups.com/forums/showthread.php?t=1154168

looks risky...  be extra cautious while dismantling... NEVER EVER short the contacts. Incase they get short even for a fraction of second, leave the Lipo on the ground (non flamable surface) and watch it for atleast 20 mins.. it may catch fire.

Be carefule while soldering. It may not be workth taking a chance ...  rest is upto you.

all the best !!!