Lipo Battery recovery?

[Bo123]

I have 2 over discharged 2200mah 3 cell Lipo batteries. They have been discharged down to about 8 volts or so. I think it was from a faulty battery powered hot glue gun that did it. Does anyone have anyway that I can rescue the batteries? They are the most important batteries, and I don't think I can afford to get more.

 

[Hondo76251]

I have 2 over discharged 2200mah 3 cell Lipo batteries. They have been discharged down to about 8 volts or so. I think it was from a faulty battery powered hot glue gun that did it. Does anyone have anyway that I can rescue the batteries? They are the most important batteries, and I don't think I can afford to get more.

It can be a bit risky to try to bring back abused lipos. If you do try, make sure you take the necessary precautions in case something goes wrong.

That said, yes you can. I use a *dumb charger* from a cheap 1s drone with a pin headder on the end. I use it in the balance lead to charge the cells individually. Be sure to get the polarity correct.

 

[Hondo76251]

Check out the 3:40 mark of this video, you'll see what i mean.

 

[Bricks]

What you are trying to do is get the voltage up high enough your charger recognizes the battery.

What I do is use my balance board using only the main battery plug for me XT60`s. Plug the low battery into the board and take a battery that is at storage level ( can be any 3 cell ) and plug the XT 60 into the balance board DO NOT USE THE BALANCE LEAD . Let it sit may take up to 20 to 30 minutes, to raise the dead battery up to a voltage that my charger will recognize, then use the balance lead and charge as normal, keeping an eye on it to see if it starts to puff.

 

[Bo123]

Ok thank you very much. I hope this works.

What you are trying to do is get the voltage up high enough your charger recognizes the battery.

What I do is use my balance board using only the main battery plug for me XT60`s. Plug the low battery into the board and take a battery that is at storage level ( can be any 3 cell ) and plug the XT 60 into the balance board DO NOT USE THE BALANCE LEAD . Let it sit may take up to 20 to 30 minutes, to raise the dead battery up to a voltage that my charger will recognize, then use the balance lead and charge as normal, keeping an eye on it to see if it starts to puff.

 

[Merv]

I agree with Bricks, the goal is to get the voltage high enough for your charger to be happy.

I use the lead acid setting on my charger. When the voltage recovers to 10v or so, switch over to Lipo balance and finish changing.

KEEP A WATCH ON IT AT ALL TIMES. Under no cerium stance, leave it unattended.

 

[Bo123]

Ok thank you all very much.

 

[mikedkelly]

I did the same thing - was trying to get my flight controller configured and thought it would just sip power from the battery. But after 2 hours my servos suddenly stopped working and when I checked the battery, the cells were under 2V. I only had 2 charge cycles on the battery and luckily the charger still recognized it, so I immediately charged it at 1C back up to storage voltage and put it in the bag for the night. I am watching it carefully and it seems to charge a little slower than its twin. If it doesn't work out, it's only a $12 lesson-learned. Now when I work on my flight controller and need the battery plugged in for servo control, I keep the balance cable plugged into my charger so I can keep an eye on it.

 

[Bricks]

A little side note I forgot to mention when plugging it back on too the charger feel the battery once in a while if it starts to feel warm stop the battery is junk.

 

[Bo123]

Hmm. I am still a little confused. What setting should I run it at? It wasn't working on lipo balance charge. IS there any other setting I should use?

 

[quorneng]

Bo123
Just be aware that a 3s LiPo taken down to 8V is most unlikely to fully recover its full capacity or be able to deliver the high amps it once did.
How much use it will be if you do get it fully charged will very much depend on its required use.
I have two old batteries that no longer can provide the power to fly but are very useful with a spare ESC for checking servo and that motors go round the right way during a build.

 

[Bo123]

Ok. I might just have to buys some more I guess. Is there anything I can use to stop this from happening again?

 

[Bricks]

Hmm. I am still a little confused. What setting should I run it at? It wasn't working on lipo balance charge. IS there any other setting I should use?

Plug in the battery as you normally would both leads and use your normal charging routine once you have the bad battery up to the voltage your charger will recognize..

Use a timer on your radio I just normally use 5 minutes and call it good.

 

[boogieloo]

Does that mean less flying time at 8 volts. Or less performance. It just runs through until your airplane crashes from running out of electric while in the air. If this does happen...

 

[bisco]

it means no flying time

 

[Bo123]

I have managed to save one battery. I won't try to save the other one, as it is very puffed.

 

[quorneng]

Bo123
It depends on what you mean by 'saved'.
A saved LiPo can show the correct nominal voltage right up to 4.2 V/cell but that does not mean it will perform as it did when new.
It will have both a reduced capacity (less flying time) and a higher internal resistance so it will give less power as well. The higher internal resistance also means it will get hotter trying to deliver the same amps as it did when new and internally generated heat is the killer for a LiPo. The result is it will deteriorate a bit more each time you try to use it.
A reduced performance may be acceptable for a 'light duty' applications but fully recovered it won't be.

 

[Bo123]

Ok. We shall see. It has returned to its normal voltage, but we shall see how it performs.

Bo123
It depends on what you mean by 'saved'.
A saved LiPo can show the correct nominal voltage right up to 4.2 V/cell but that does not mean it will perform as it did when new.
It will have both a reduced capacity (less flying time) and a higher internal resistance so it will give less power as well. The higher internal resistance also means it will get hotter trying to deliver the same amps as it did when new and internally generated heat is the killer for a LiPo. The result is it will deteriorate a bit more each time you try to use it.
A reduced performance may be acceptable for a 'light duty' applications but fully recovered it won't be.