Can a lipo pack be repaired.

[Wheels]

I have a 12 s stick pack...well actually 2 of them that have dropped a single cell as it reads zero. Can this be repaired anywhere? or can I drop 2 cells out of them and use them as 10s packs. Any ideas.?

[GIXERMAN]

Yes can be sorted with the correct no how and soldering ability.

[Kisana]

After having a few 6 cell packs fail, I now buy 3 cell packs then put a link plug on to parallel together on the heli. then if one pack fails its less £ to loose...

[VOLT]

Ive "Fixed many 0 volt cells before" and they still run perfectly today...I put my charger into NiCad mode and put 1 amp output, then make a servo lead with 2 long gold connectors exposed so you can tap into the balance lead,find which cell has gone down with a multi meter..if you don't know how to do this then you should not be attempting this procedure at all! charge it until the voltage comes up to a point where my Hyperions can take the voltage further, the make it a single cell at whatever the mah is and charge that cell until it reaches the other cells voltages then you balance charge them all at once...while you charging in NiCad mode just keep your hand on the pack and if it just slighty becomes warm stop the process and do it again when its cold.etc etc...just keep checking that cell if you fly the packs often enough they recover very well if you leave them standing and they die..time to move on and cut the rot out! I buy a sacrificial pack a 2s would normally do with the same c and mah and strip down and replace

[pgkevet]

I donlt know if they're still around but the original tiny Esky chargers used to charge through the balance lead.. either 2S or 3S sockets onboard.. and were very forgving about charging packs conventional chargers wouldn't touch. isolating the dud cell + one other through a 2X converter is another way of recovering packs to a state that my hyperion would then take over from. The usual precautions apply.

I've got 3 ^S packs with a dud cell at the moment but since they're a few years old I'm binning them instead of bothering 'cos they'll be on the way out anyway....and a tad puffy

[milly0812]

Ive "Fixed many 0 volt cells before" and they still run perfectly today...I put my charger into NiCad mode and put 1 amp output, then make a servo lead with 2 long gold connectors exposed so you can tap into the balance lead,find which cell has gone down with a multi meter..if you don't know how to do this then you should not be attempting this procedure at all! charge it until the voltage comes up to a point where my Hyperions can take the voltage further, the make it a single cell at whatever the mah is and charge that cell until it reaches the other cells voltages then you balance charge them all at once...while you charging in NiCad mode just keep your hand on the pack and if it just slighty becomes warm stop the process and do it again when its cold.etc etc...just keep checking that cell if you fly the packs often enough they recover very well if you leave them standing and they die..time to move on and cut the rot out! I buy a sacrificial pack a 2s would normally do with the same c and mah and strip down and replace

Very interesting at what voltage will the cell be ok to put on my PL8 ? after nicad mode ?

[Dorlingus]

If a cell has drops below 3V and for any sustained length of time, it will cause irreparable damage to the cell. It may bounce back by fooling it on your charger, but it will never by as good again and it's a dangerous thing to do, especially if the cell is shorting internally. I'm talking from experience! I would always remove that cell as it will fail before the others and usually not many cycles later.

I've repaired many packs. You just need a good soldering iron (100W), solder sucker, a credit card and a bit of patience. Get your mrs nail varnish remover (acetone) and that seems to dissolve the glue holding cells together, but use sparingly. Careful not to short any of the cells with a soldering iron or with a bit of solder that runs off from one cell to another, it'll make you jump!

[Rob Barnes]

If it was me and im no expert on repairing lipos, I would just chuck it and buy new, Having nearly burnt myself badly plugging packs in the wrong way and seen a few go up, I would even attempt it sorry !

[cjcj1949]

I wouldn't try to recover a cell at 1 amp. Perhaps 100ma, but even then you are playing with fire. The chargers won't charge for a reason. I've recovered NimH and NiCd cells by clearing the short with high current, but they don't go up in smoke.

[VOLT]

I wouldn't try to recover a cell at 1 amp. Perhaps 100ma, but even then you are playing with fire. The chargers won't charge for a reason. I've recovered NimH and NiCd cells by clearing the short with high current, but they don't go up in smoke.

some people dont jump out of planes some do depends on what you are willing to try....I wouldnt hehe

done it many many time's without any proplems you just spiking the pack to become active again....you dont plug it in and walk away like a muppet and hope for the best! the packs ive repaired are still working 50 cycles later 100ma you will be there all day
you only need a few volts in the cell for the LIPO charger to pick it up and continue its charge ...ive been doing this for years and never had and explosion or puff or anything like that at all..if you would like to see a vid of it I will make one the next time I fix a cell
and to answer milly0812 what voltage for the recovery in lipo mode....it 1 CELL 3.7v at whatever the MAH is of the cell
obviously there are many reasons for the cell failure , Ive been lucky with 30 or so ive brought back to life it seems, had a few that did not recover at all and they are replaced