lipo cooked?

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lipo cooked?

Postby quarry44 » Wed Apr 25, 2012 4:14 am

I have a Turnigy 1300mah lipo,25c-35c,which has only had 4 or5 use cycles.I accidentally left the voltage beeper on the balance plug when putting it in my safety bag.I didn't get around to charging batts for a couple of days,and when I took the battery out of the bag,the beeper's lights had all gone red.
When checking the battery,I got these results:cell1-3.17v,cell2-3.17v-cell3 4.12v.
I thought I might save it by using the chargers discharge function,so I did that,let the battery rest for a couple of hours,then tried a charge.The results were not pretty:
Cell1-3.98,cell2-3.98-cell3-4.55v!.I've never seen such a high voltage in 1 cell(in all my 6 months of lipo ownership :oops: ).
I even tried discharging again,and slowly charging to 9.9v using the Nimh setting,as I had been told that can sometimes save a bad lipo.Then charged up to full capacity again using lipo setting.same result as above.
I know I can't expect much from a $7 battery,but want to avoid this sort of cock-up in the future.
Is this battery ok to keep for testing,etc,or should I chuck it in the bin?
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Re: lipo cooked?

Postby Hallmark » Wed Apr 25, 2012 6:33 am

All I can say is there are ways to recover the battery and you'll find the step-by-step videos on YouTube BUT I do not recommend these practices as they are volatile and could result in explosions and injury so please be extremely careful!
"I am prepared to meet my Maker. Whether my Maker is prepared for the great ordeal of meeting me is another matter." Winston Churchill
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Re: lipo cooked?

Postby cynr100 » Wed Apr 25, 2012 9:15 am

Hi quarry44, lots of vids on UT show exploding LiPos at various stages :shock: .
The best policy, if in doubt get it out of the house.
My LiPo "safe bag" is a concrete besser block 8-) .
Its only $7 ?? so buy another for piece of mind and ensure you have a good charger and watt meter (I use the Accucell 6 and HK-010). Through all my misadventures to fly I have charged my 3 batteries the night before and failed miserably to fly more than 20seconds, but on return I have always made sure to return my batteries to storage charge (3.8v per cell approx) using the battery charger and then the watt meter to check and correct balance. I sleep well at night :lol:
Not enough time in the day for all my crazy ideas, I'm not slow, I'm just pacing myself
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Re: lipo cooked?

Postby BillGriffiths100 » Wed Apr 25, 2012 1:01 pm

If the battery is going over voltage suspect the charger. The battery cannot charge itself, the charger should have cut off at the correct voltage, you can't blame the cell for overcharging itself.
Check other batteries you have charged on the charger the same situation might apply to the same numbered cell in the packs.
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Re: lipo cooked?

Postby Shotglass » Wed Apr 25, 2012 6:22 pm

BillGriffiths100 wrote:the charger should have cut off at the correct voltage


it did it stopped charging correctly at 12.6v which is the cutoff for a 3s lipo
the issue is that the thread startet for whatever reason chose to charge instead of balance charge a severely out of balance lipo pack which is pretty much guaranteed to damage the cells and can possibly be dangerous
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Re: lipo cooked?

Postby BillGriffiths100 » Wed Apr 25, 2012 7:10 pm

Yes, let me qualify that you should use a balancing charger for lipos and that as shotglass points out is probably not what you are doing.
I had assumed that you were using one!
Get a good balancing charger and the problem will be solved.
Compromising with out of control government is like living with a lion, sooner or later the bloody thing will eat you .

You accept the tyranny of the state when it's not being applied to you, when it is: it's too late.
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Re: lipo cooked?

Postby quarry44 » Wed Apr 25, 2012 8:41 pm

Yes,I should have mentioned that I did in fact use the balance charge function of my Turnigy 70W charger.I charged several other packs the same day,and they all charged correctly.Obviously leaving the beeper thingy connected killed 2 of the cells.It's going in the bin.
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Re: lipo cooked?

Postby cynr100 » Thu Apr 26, 2012 1:34 am

Don't forget to defuse your bomb, I understand that 6 weeks in a bucket of brine will deactivate. I prefer the SWMAC method, slab of concrete and stab it (the battery) with a sharp shovel and allow each cell to expend itself, standing upwind of course.
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Re: lipo cooked?

Postby quarry44 » Thu Apr 26, 2012 4:39 am

yes ,I have seen umpteen different methods of disposing of lipo's,some apparently more dangerous than just piffing it in the bin!But i'm being a responsible citizen,they're in a bucket of water as I write/type this.I wasn't aware it had to be salt water though.I wonder what the reasoning behind that is.Corrosion?Breaking down the polymer?
Inquiring minds want to know :mrgreen:
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Re: lipo cooked?

Postby BillGriffiths100 » Thu Apr 26, 2012 8:21 am

I feel that you must have had a charger malfunction with this pack, maybe to do with the balancing lead connections.
Too late now it is sacrificed!
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