RC India

RC Equipments => Batteries and Chargers => Topic started by: azhaguvel on April 17, 2011, 07:35:23 PM



Title: Dead Lipo - No LIPO never gives up
Post by: azhaguvel on April 17, 2011, 07:35:23 PM
Yesterday I was doing some scratch building & left my transmitter on, which is using a 1450 mah LIPO battery. I noticed it was on only today afternoon  :banghead:. Obviously the LIPO was dead. It read 3.4 V for all the three cells & around 1.1 V per cell. When I used the LIPO charger to charge it, it was showing error that the volt is too low. I was searching in the net & found that to bring back a dead LIPO, charge it in NIMH mode then use the balance charge to bring it back to life. Yes it worked I charged the LIPO in NIMH mode with 500 mah as input for half an hour (was frequently touching it & testing it whether it’s getting hot or bulge, also had a bucket of water nearby. I was doing this in open space). After half an hour charge the individual cells came to 3.7 V per cell then I used a normal balance charge, now it’s a happy LIPO  ;D ;D ;D working as usual.

LIPO’s have nine life’s  :giggle: unless they die by old age   ;)


Title: Re: Dead Lipo - No LIPO never gives up
Post by: clayboy on April 17, 2011, 07:41:38 PM
a slow discharge is not so bad and they will normally survive, maybe loose a little bit of performance but in a radio i daube u ever will notice


Title: Re: Dead Lipo - No LIPO never gives up
Post by: Divyam on April 17, 2011, 08:06:02 PM
That's great!

also had a bucket of water nearby.

As far as I know, IF there had been a LiPo fire, shouldn't you use sand instead of water? I've heard water just makes electric fires worse..


Title: Re: Dead Lipo - No LIPO never gives up
Post by: asinghatiya on April 17, 2011, 09:30:41 PM
wot if a cell didnt give any charge...my 3 cell LIPO all of a sudden start showing error and when I tested individual volts..one cell was on 0 volts and total volts were 8.2 v.

I removed the dead cell and replaced with a working cell.

Can i recover the dead cell....?? this cell was alive just a flight back and all of a sudden .... :banghead:.



Title: Re: Dead Lipo - No LIPO never gives up
Post by: azhaguvel on April 17, 2011, 09:47:04 PM
@asinghatiya

I am not sure about that but try charging it and see whether you are able to recover it. Solder long wire with it keep it away from the charger, outside in a open space & charge it for some (5 min) & check whether it is gaining some volts. If so do recover the cell.

@divyam

The idea was, If the cell catches fire turn off the supply & pore the water on it. I am sure that it wont catch fire before bulging.


Title: Re: Dead Lipo - No LIPO never gives up
Post by: CrazyPilot on April 17, 2011, 09:53:55 PM
Try this for all kind of bad lipos. be it one dead cell, unbalanced etc.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=2055



Title: Re: Dead Lipo - No LIPO never gives up
Post by: Samanth on April 27, 2011, 11:59:02 PM
by discharging a lipo under 3.0v or overcharging above 4.2v DECREASES the life cycle of your Lipo...

1 cycle = 1 Charge and 1 Discharge

A quality lipo has 250-300 cycles
Chinese lipos have under 200 cycles

After you've left it discharge slowly to 1.1v PER CELL, its life cycles have greatly decreased !

and yeah, use sand instead of water.., cutting off oxygen for combustion is ALWAYS better than adding water to it :D



Title: Re: Dead Lipo - No LIPO never gives up
Post by: Vector on April 28, 2011, 12:25:29 AM

Can be done but not a good idea to recover a dead cell..anything can happen.
In the past i tried to recover a almost dead cell of my 3s Hyperion by above mentioned NiMh method..it exploded on my car ! Nothing, just a loud pop.
 iF U want to recover dead cells.. DO IT OUT IN THE OPEN and certainly not on/near ur car!.


Title: Re: Dead Lipo - No LIPO never gives up
Post by: sunk? on April 28, 2011, 01:35:03 AM
hi guys,
I had this happen to me .......1 cell suddenly dead..............
I opened the outer sleeve and found a wire was off one cell.
worth looking if it appears to take no charge.
carefully open 'OUTER SLEEVE' if you puncture the cell sleeve IT WILL explode
regards
don


Title: Re: Dead Lipo - No LIPO never gives up
Post by: shashank32 on March 29, 2014, 12:09:58 PM
I forgot to unplug my battery from my quad after a flight and it just sat ghere for about 14hrs. When i plugged it to a voltage alarm it wouldn't even turn on. I charged it with the Wolfpack B3AC charger from RCBazaar and two of the cells came back to life while one of it still reads 0v. I checked it with a multimeter and it shows about 5 to 10 milli Volts !!
Bought an Imax b6 from quadkopters.com and tried to charge it in NiMh mode for about an hour at 0.5A, but still the cell wouldn't charge, it stays at 0 volts. The battery isn't puffed up nor is getting hot while charging. Can it be recovered by any means ?


Title: Re: Dead Lipo - No LIPO never gives up
Post by: Propfella on January 19, 2015, 05:29:08 AM
Hi shashank32 I'm sorry to say there's nothing you can do with a cell which shows no life or a very low voltage such as yours. However, it could be a bad connection, I've had two lose a cell due to wiring problems. If I was younger I'd attempt removing the faulty cell and adding a good cell if it was available. But, age brings a little shake to my hands and I prefer not to have a battery go SPLAT as I short a connection out. :-) If you don't suffer from the shakes and don't have a spare cell, simply remove the dead cell and make a 3s into a 2s.