How to repair an overdischarged or puffed lipo

Ok for the third installment of me being bored with the new phone, I will show how you can deswell a lipo and save them.  [size=12pt]Keep in mind again that I am not liable for anything that may happen from you attempting anything I do yourself.[/size]  That being said I have heard many times that a lipo cannot be saved after being puffed or over discharged, this is not necessarily true.  It is always in my opinion worth a shot to try and save a $70+ battery.  In this instance I have two Venom 5400mah 2S lipos that were left in my Hoboa.  I checked the cells and found them all to be less than 1volt per cell  and also puffed from overdischarge.




So the first thing you need to do is start charging the cell, using the nimh setting in your charger set it at .1mah and let it charge, periodically checking cell voltage of both cells and also make sure that the pressure in the pack does not become to great, my way of doing this is to squish the pack with my finger and if I can dimple the pack a bit then it's ok, if the pack becomes very hard then stop charging and let it rest.



After getting the individual cell voltage above 3.3 volts then it's time to freeze the pack, Lipo's are sealed cells and have no vents (this is the reason they puff) what your doing by freezing them is calming the excited molecules in the pack and attempting to reorganize them.



While your battery or batteries are in the freezer I like to induce pressure on them to help the deswelling effect.  You need to make sure both surfaces that are pushing are flat, in my case two sets of cards and 3lb's of beef patties lol.




After a few hours of cool-down check the batts and see how they have done, in my case this will continue tomorrow as I left them in overnight as it was WAY to late when I started this.  I will let everyone know tomorrow how this went and test the packs capacitance to see if they were hurt, in many cases the capacitance of the pack will be hurt some.  Most that I see is usually 10% of the total capacitance in gone.

Don't those patties grill up into a fine burger.  ;D
I have some in my freezer too. 

And I just disposed of an almost new 6 cell that one cell went bad on.  :'(
Can you charge a single cell with out taking the pack apart?

I gave Sinistercad a 3S LiPo that had one bad cell.  I was kind of hoping he would post that repair here somewhere.

You can charge one cell through the balance connector if needed, I'm sorry John but I repaired that battery before I even thought about making the post's here.  If I get another one I will post the repair.

Huh...i wondered if this was possible.i prolly got 5 or 6 lipos that are smoked.my son keeps leaving the crawlers plugged in and it draines em....

Well here is the end result, Lipo is deswelled and has a full charge now, after you deswell and charge the lipo you need to "jog" the battery as it's called or use it to regain it's capacity.  Here are some pics of the end result.

Wow....ima try this.try and save some batteries