over discharged lipos. what do i do?

[Ryan]

my plane was in a tree overnight.

etec 1700mah 3s lipo pack over discharged.
can't charge.

what do i do?
does anyone know how to individually charge the cells and put the pack back together again?

[nic]

Cool!! You got it down?!??!

:-)

Find a place very safe....
Get ready fire-fighting equipment...

either:
1) Set to a low cell count and try charging...

or
1) Use a Nicad/Nihm Charger, set to trickle charge.

2) Check every five minute... stop when you recover to above the minimun voltage.

But.... is it worth the risk?

[PhiBeR]

U gotta find a computer charger and charge it at 0.1C..
Why computer charger? coz normal chargers can't charge at 0.1C..

Keep charging the batt and monitor it for bloating/heat/etc..
If got then stop lor.. the pack is lemion le..
FYI, dun use normal fire extinguisher or water on Lithium...
They will make the fire worse..

Then pass to us for next week jalan bahar funfly..
Super-Hornet and me thinking of recreating a SG version
of the exploding lipo pack video!

[Super-Hornet]

Yeah... I would love to do some pyrotechnics also. We may want to test whether charging at 10C or more can explode it or not as well.

Super-Hornet

[Ryan]

wah you all damn evil man!
haha but anyway no way i can fix it for sure?

[Ryan]

Originally posted by nic
Cool!! You got it down?!??!

:-)

Find a place very safe....
Get ready fire-fighting equipment...

either:
1) Set to a low cell count and try charging...

or
1) Use a Nicad/Nihm Charger, set to trickle charge.

2) Check every five minute... stop when you recover to above the minimun voltage.

But.... is it worth the risk?

should i set to a 1 cell count and charge?
and what about the other setting?

[Ryan]

Originally posted by PhiBeR
U gotta find a computer charger and charge it at 0.1C..
Why computer charger? coz normal chargers can't charge at 0.1C..

Keep charging the batt and monitor it for bloating/heat/etc..
If got then stop lor.. the pack is lemion le..
FYI, dun use normal fire extinguisher or water on Lithium...
They will make the fire worse..

Then pass to us for next week jalan bahar funfly..
Super-Hornet and me thinking of recreating a SG version
of the exploding lipo pack video!

where can i find computer charger?

[PhiBeR]

Borrow a schulze or triton..
Or pass to anyone willing to charge for u bah..

There's a chance ur batt is okay..
Juz need to trickle charge it to see..

Btw, wat's the volatge of the pack now?

[Fit]

Do like what Phiber recommended. It will save your lipo from the rubbish bin. The pack won't be quite as punchy as before but its still good for many more cycles.

Remove the shrinkwrap and via the PCB tap to each individual cell.
Any thing that outputs like 100ma and 4V is usable to charge the battery. While charging, hook the voltmeter to the battery being charged and monitor its voltage. It will rise very quickly so don't panic.

Once it reaches around 3.6V, you can remove it and charge it as per normal. On the first charge its best if you can charge the cell individually till full charge all the while monitoring the cell's voltage and temperature.

Take precautions though while trying to revive the pack... I would do it in the corridor or at the MSCP just in case

[nic]

-- I got computer charger... from infamous Chan....
-- and I happen to be going fun fly at Jln Bahar, next Sat again...
-- and it also happen that they want to film the explosion there.......
-- and it also happen I curious to see how it going to explode.....
--- and you know how trust worthy Ah Chan's things are.....
... yar seriooooouuuuuuusssssssss.... this one gooooooooooood...... just 1 of the 2 out of the many things I got from him that actuallllllllly work.....

[nic]

Originally posted by nic
-- I got computer charger... from infamous Chan....
-- and I happen to be going fun fly at Jln Bahar, next Sat again...
-- and it also happen that they want to film the explosion there.......
-- and it also happen I curious to see how it going to explode.....
--- and you know how trust worthy Ah Chan's things are.....
... yar seriooooouuuuuuusssssssss.... this one gooooooooooood...... just 1 of the 2 out of the many things I got from him that actuallllllllly work.....

realllllllyy!!!! I no bluff u!!!
I still using it to charge my Tx batts....
Reallly one!!!!

[PhiBeR]

But then hor....

Ur computer charger dun have lipo setting leh...
But it can used to simualte explosive..

We set voltage/cell count to MAX..
and Amp rating to MAX..

Then use a 3 metre wire to charge the lipo batt at one corner..
Then hor.. we SIAM and see fireworks!!

I seriously think we shld do a controlled simulation to warn the newbies
how dangerous lipos can be if they dun tke care of them!
Then hor.. we also want to see a real explosion mah..
Long time no see since grenade range.. heehee..

[nic]

Loyn ah.... can we borrow your car battery?

[nic]

Originally posted by nic
Cool!! You got it down?!??!

:-)

Find a place very safe....
Get ready fire-fighting equipment...

either:
1) Set to a low cell count and try charging...

or
1) Use a Nicad/Nihm Charger, set to trickle charge.

2) Check every five minute... stop when you recover to above the minimun voltage.

But.... is it worth the risk?

Caution:
End results:

http://www.daddyhobby.com/forum/showthread.php?s=&threadid=1825

It is not worth the risk.

[BonJour Brat]

It should "recover" itself to the safe 3+ volts per cell, then charge it as usual.
I just discharged a 2s etec to 3 volts few weeks ago.. left it alone for some time for it to self recover till it rose back to 6.4V, then charged it. yet to use it but it should be fine