RC India

                         My 2200 mAh 3S wolfpack LiPo served me very well for how I used it. Even after directly charging the pack with 12V o/p from a SMPS and discharging it too low to 8 or 9Volts several rounds (The times when I don't had a LiPo balance charger and Low voltage alarm) it worked like a Charm.
 Forgot to un connect the battery from my quad one day , and next day the voltage levels where -1V, 1.x V and 1.xx Volts each cell !
However With some efforts brought the pack back to life again - with 5V mobile chargers and stuff .

I again could use the pack for another tens of cycles I think (Still rough use SMPS charging,Over discharging !!) -

Then I got an Imax B6 for a few days use from a very helpful friend, Subhash (Thanks again Subhash :))

Wah! Finally my LiPo is going to be charged correctly - but what happened is the most funny part  :giggle: charged the LiPo in correct mode (2.2A , 3S) and after half an hour Phizzsssssssszzzzz !!!! When I ran to my room to check what the hell it was - Well It was such a horrible smell  :giggle: - the Battery pack was found to be very hot.

All this happened few weeks back, I have kept LiPo on my Attic - Last day while searching for something else Found this again....
Got it to the work bench for a Postmortem  :headscratch:

I will Post the findings here in this thread .......
Later found one cell in this pack is still pretty good (:|~

I have already looked under the Hood of a single LiPo cell from the pack (The one that Blasted) , out of the other two cells, one is puffed up like a Puffer fish  :giggle: And as already said, one is still in perfect condition.

Will post the pics of inside the LiPo cell soon.... with explanation of chemicals and it's working  :hatsoff:

2.2C charging current for 2200 mAh 3S wolfpack is too high, did you mean 2.2 Amps?

RCB recommed 1amps charging current for 25C battery.

Thanks, Akhil eattan, Edited :)

More over, this LiPo was being charged directly with a 12V SMPS O/P that has max. 16A supply !!!

I think the LiPo didn't really liked the change from Rough use to Normal use :giggle:

Here is the Cells I collected from 3S 2200mAh wolfpack, and another 1 cell damaged 2S zippy battery.

(http://i1061.photobucket.com/albums/t471/soorajspn/LiPo%20story/chinastamp005_zpsc3a5add1.jpg)

out of this the burst one will be opened up to Look inside :)
the working ones will be recombined to make another 2S pack for testing purposes.

be cautious. non fully discharged battery chemicals exposing to air should cause fire. better don't try to open cell to see chemicals.

The battery was fully discharged at time of opening (Already done in the early morning ;D)

The SMPS you were using is not designed to be a charger, hence it provides a lower output of ~12 volts, hence no damage to the LiPo Pack even after it being rated at 16Amp since it never made the voltage of the LiPo Pack exceed it's limits. As soon as the voltage of the pack reaches the voltage of the SMPS (~12 volts), nothing flows through anywhere since at that moment, they both are at same potential energy.
Chargers on the other hand pushes in higher voltage in order to have some potential over the voltage of the package for the easy flow of current and easy charging.

The continued abuse with SMPS made the cells unstable and when you connected it to a proper charger (Which uses a higher voltage than a SMPS), the cells couldn't take it anymore and gave up.

Everything that you have mentioned in this thread, right from charging directly through a SMPS, leaving it unattended while charging and dismantling a pack is something i personally consider highly irresponsible since the safety factor was thoroughly overlooked and i strongly advise beginners to stay away from such experiments.
LiPo explosions usual catch fire (You were lucky) since Lithium burns furiously upon contact with oxygen. These puffs, when catch fire, burns and melts everything in their path.  

If you would have invested few hundred bucks in getting a cheap B3AC charger form a LHS (Which would have meant getting the charger in hand pretty faster than your favorite eBay.com), then today you would had a LiPo + a charger. But now you have nothing of the two.
I guess eBay.com not always means saving money ???

Dear Sooraj, do you have any idea how dangerous it could had been? fire? life threatening situation?

Please be careful while using charging and storing LiPo

That is new info . :headscratch:


I agree to this 100% ....Don't recommend any of this to be tried by anyone
 --- still A LiPo is not a BOMB ----(I don't want any youtube videos coming up just explaining this sentence)

I am not against LHS - this being said, with the budget I started making a quad, I had no choices ... months of searching provided me lot of info. and also cheap sources.

Thanks for the suggestion Satya sir :thanks:
I always am :)

hi sooraj, one of my wolfpack was also puffed, but not like yours, i left mine for few days and it came back to normal!! and the surprise is, it is performing good!! and i hope by discharge you mean immersed in salt water for enough time!!

regards,
JK

LiPo packs Puff up due to the chemical changes ... so a small Puffing during discharged state or due to long storage is normal - The pack can be brought back to normal by a Charge cycle, that might have happened to your Battery pack..

For me, I haven't used salt water or any thing, My cell was already Blasted ... and It was Kept Idle for at least a Month.. It was completely Discharged, and as the pack is not sealed and was open to the atmosphere for long time, It was also chemically Inactive...

Hope to use the other super puffed cell for a Fire test (Under extreme care)

While LiPo's don't necessarily explodes with the exact same destructive force of a bomb, the temperature of the fire from the puffed cells is usually very high. That's why trying out something dangerous like what you have done should always be outside on concrete, etc and not inside.
Leaving it unattended and coming back finding the smell might have also resulted in (touch wood) coming back and finding out the contents in the room burning.  >:D

Hope it makes sense.

I hope not something like this!!

http://www.youtube.com/watch?v=coX0SwubG4A#ws (http://www.youtube.com/watch?v=coX0SwubG4A#ws)

Hah!, Subhash Everybody have seen these videos :)
Still--- no problem :)

i just meant take better precautions and not act like those people in the video!!

regards,
JK

That much be the Do's and Don'ts ........

I don't want anyone to try this out .. I don't recommend anyone to perform this.

The Fire proof :headscratch: wrapping removed :
(http://i1061.photobucket.com/albums/t471/soorajspn/LiPo%20story/LiPosurgery005_zps6a652b8d.jpg)

The white plastic like substance I initially thought It is just a wrapping Later understood it is the Porous Polymer Electrolyte.  :giggle: - the reason for word 'Polymer' in a 'Lithium Polymer' !

(http://i1061.photobucket.com/albums/t471/soorajspn/LiPo%20story/LiPosurgery006_zps7bef4fd3.jpg)


Now further in to find the Lithium ...

Unwrapped two - three layers to find this Black Slurry like substance... (Still couldn't find out what it is)

(http://i1061.photobucket.com/albums/t471/soorajspn/LiPo%20story/LiPosurgery008_zpsaf104be4.jpg)

Edit : Just found the Black slurry is A thin layer of the slurry of carbon and lithium material :)

The slurry is a mixture of carbon and lithium. You might find this link interesting: https://learn.sparkfun.com/tutorials/how-lithium-polymer-batteries-are-made

The Electrode foil (Aluminum) Surrounded by a thin layer of the slurry of carbon and lithium material is stacked In between two layers of Porous polymer
(http://i1061.photobucket.com/albums/t471/soorajspn/LiPo%20story/LiPosurgery010_zpsc1a11b3b.jpg)

Edit: SK, what a coincidence, I just found info. from the same place you referred !!

The Aluminum Foil coated in a thin layer of the slurry of carbon and lithium material is the ANODE in a LiPo cell.

The cathode is Copper Foil - Which will be stacked between two layers in the other side of porous polymer Electrolyte. (Polymer is stacked in a zig-zag structure.)

(http://i1061.photobucket.com/albums/t471/soorajspn/LiPo%20story/Lithiumpolymercomposition_zps08af6e9a.png)

(http://i1061.photobucket.com/albums/t471/soorajspn/LiPo%20story/LiPosurgery016_zps8af9a18f.jpg)

(http://i1061.photobucket.com/albums/t471/soorajspn/LiPo%20story/LiPosurgery012_zpsce33aed7.jpg)

(http://i1061.photobucket.com/albums/t471/soorajspn/LiPo%20story/LiPosurgery016_zpsa6c8f6f2.jpg)

A conclusion -
Cathode : thin Coper foil covered in thin layer carbon paste
Anode   :  thin Aluminum foil covered in a thin layer of the slurry of carbon and Lithium

Electrolyte : Thin Porous semi permeable Polymer membrane

The Internal structure comprises of mostly solid.

The material which covers all these up is just a kind of hard plastic !! Initially I thought it will be heat resistant or what:giggle:

You've got balls of titanium alloy holding that lipo bare handed like that.
I wore a full face helmet and leather jacket to rip off a cell from a 3s cut by a prop.

PS, It's not at all safe to cut open battery packs like that without a controlled atmosphere and safe disposal methods for environmental and health hazard reasons; Lithium poisoning is not a joke.  Don't ever do that. The internet has enough videos and pictures to satisfy such curiosities.

@SOORAJ why do you always have to do things that are not supposed to be done it is dangerous
And if you still want to continue doing it please dont post on the forum as ten other curious readers may attempt to do it
PLEASE POST RESPONSIBLY
And if you dont know you can ask people before doing it
Health Hazard is a big NO

http://www.lenntech.com/periodic/elements/li.htm (http://www.lenntech.com/periodic/elements/li.htm)

http://en.wikipedia.org/wiki/Lithium (http://en.wikipedia.org/wiki/Lithium)

Composition Information on Components

Component                  Approximate Percent of Total Weight

Aluminum                                         2-10%
Aluminum Packaging Foil                      5-15%
Carbon (Various Forms)                      10-30%
Copper                                             5-15%
Lithium Cobalt Oxide                           20- 40%
Lithium Salts                                     1-5%
Nickel                                               0.5-5%
Organic Carbonate                              10-25%
Polymer                                            3-10%


Disposal Procedure of Lithium Ion or Generally Lithium composition Batteries :
LITHIUM-ION Polymer cells and batteries contain no toxic metals, only naturally occurring
trace elements How ever, the cell/pack must be fully discharged or Inactive . It is advisable to consult with local authorities as disposal regulations may vary dependent on location.

When a Lithium Battery Heats up abnormally, or has got on flames - best nearby extinguisher is Water itself (Had a confusion in this part as Lithium as an alkaline metal, in pure form reacts easily with water - but In a Lithium composition Battery/Cell there is no Pure form Lithium metal)

Extinguishing Media: Dry chemicals, water.
Fire-Fighting Procedures:
Use self-contained breathing apparatus and protective clothing.

Toxic gases (HF, PF6) will be formed if cells or battery are involved in a fire. Cells or battery may flame or leak potentially hazardous organic vapors if exposed to excessive heat, fire or
over-voltage conditions. Damaged or opened cells or batteries may result in rapid heat and
the release of flammable vapors.