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Feb 16, 2009, 05:56 PM
Registered User
Help!

dead lipo how to charge it


i have a 2 cell lipo by tenergy nd i left it on my airplane over night i have tried to charge it on a e flight balancing charger but it just has a chrging error so how can i charge my battery? help
Last edited by fasstrc925; Feb 16, 2009 at 06:06 PM.
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Feb 16, 2009, 06:14 PM
Novice RC pilot
u.rusty's Avatar
Is the battery completely dead? Have you checked the voltage of each cell with a multimeter?
Feb 16, 2009, 06:23 PM
Registered User
yes completely dead is there any way i can charge it
Feb 16, 2009, 06:46 PM
Pilot not Drone Operator
hallstudio's Avatar
you need a nicd or nimh charger and do a slow charge .3C untill you hit 3.25 volts per cell then charge with the ballance charger.
Feb 16, 2009, 06:51 PM
Registered User
thanks
Feb 16, 2009, 07:11 PM
Registered User
yay it works now thank you hallstudio
Feb 16, 2009, 09:48 PM
Space Coast USA
hoppy's Avatar
Don't get your hopes up too high
It's not going to be as good as a new one and may go down hill rapidly.
Feb 16, 2009, 11:05 PM
Registered User
its simple just get a portable defribillator and shock the batteries back to life!!
Jun 28, 2009, 08:46 PM
Registered User
I have an 11.1V 3 cell 2200mAh 20C li-po that is throwing a charge error on my e-flight charger, and will not charge. According to my volt meter, it's still kicking out 7.4V, so it's not been discharged too much. The charger is flashing both red and green lights in unison, indicating that the battery pack has been excessively discharged. The pack is practically brand new.

does anyone know of a possible remedy, other than buying a new battery pack? Unfortunately, the little e-flight single charger is all I have right now.
Jun 28, 2009, 09:06 PM
Registered User
ebill3's Avatar
Quote:
Originally Posted by stuhrw
According to my volt meter, it's still kicking out 7.4V, so it's not been discharged too much.
On the contrary, it indeed has been discharged too much - way too much. Several minutes after flight, it ought to show a minimum of 3.7 volts per cell.
Quote:
does anyone know of a possible remedy, other than buying a new battery pack? Unfortunately, the little e-flight single charger is all I have right now.
See post #4. Perhaps you can borrow a Ni charger. If you do, closely monitor the voltage and stop charging with the Ni charger when the pack reads 3 volts or more per cell.

Bill
Jun 28, 2009, 09:07 PM
Registered User
smurf's Avatar
Quote:
Originally Posted by stuhrw
I have an 11.1V 3 cell 2200mAh 20C li-po that is throwing a charge error on my e-flight charger, and will not charge. According to my volt meter, it's still kicking out 7.4V, so it's not been discharged too much. The charger is flashing both red and green lights in unison, indicating that the battery pack has been excessively discharged. The pack is practically brand new.

does anyone know of a possible remedy, other than buying a new battery pack? Unfortunately, the little e-flight single charger is all I have right now.
3s packs should not be discharged under 3.0 volts per cell and better to stay above that. You may have one bad cell and 2 good ones. If you can check each cell, it wil tell you for sure. If it's one bad cell, chances are you can't get it back to normal.
Jun 29, 2009, 04:44 PM
Registered User
OK....I have a nicad charger, but the connectors are different. My nicad only has 2 wires, whereas the 11.1V lipo has 4 wires on the connector. Can I simply attach the nicad charger to the 2 larger ESC wires on the battery using bullet connectors? I'm not an electrical engineer, but it should work, the same, right? Power out--power in?
Jun 29, 2009, 05:34 PM
Registered User
ebill3's Avatar
Quote:
Originally Posted by stuhrw
OK....I have a nicad charger, but the connectors are different. My nicad only has 2 wires, whereas the 11.1V lipo has 4 wires on the connector. Can I simply attach the nicad charger to the 2 larger ESC wires on the battery using bullet connectors? I'm not an electrical engineer, but it should work, the same, right? Power out--power in?
Yes. Use the Ni charger to charge the LiPo by means of the ESC connector. Again, do monitor the voltage and stop at about 9 volts. Try the LiPo charger. If still too low, go for 10 volts using the Ni charger.

Bill
Jun 29, 2009, 10:39 PM
Registered User
Quote:
Originally Posted by ebill3
Yes. Use the Ni charger to charge the LiPo by means of the ESC connector. Again, do monitor the voltage and stop at about 9 volts. Try the LiPo charger. If still too low, go for 10 volts using the Ni charger.

Bill
You da' man, Bill! It worked. I now understand about not discharging lipos too much! My battery has 3 cells, total voltage was down to 7.5v, which is a little less than 3v per cell.......not good. I hooked up my Ni charger (after soldering on some deans connectors) and monitored the voltage as it trickled in. After about 30 sec, the voltage was up to 9.5v, so I stopped. Plugged it into my lipo charger and was good to go! Charged it up, readjusted my low voltage cutoff in the esc, and went for a flight. No noticeable battery degradation noted. Still got over 10 min of flight time before low voltage kicked in. Thanks again!
Jan 14, 2011, 02:02 PM
Registered User
Mine was dead too. I took two wires and hooked it up to a 9 volt battery through the bositive and negative outlet to the plane. I taped the wires to the 9 volt battery. I plugged it in and it started to blink more than 3 times. I watched it for less than five minutes then unpluged the 9 volt. It fooled the charger into thinking it had more than 3 volts. Don't know if thats dangerous, but it worked.


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