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Lipo Fire what's the real deal ????

Old 03-30-2007, 01:49 PM
  #1  
skiman762
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Default Lipo Fire what's the real deal ????

Ok
I've read lots of post from people who have HEARD about lopo fires
HEARD this HEARD that
But has anybody actually had a lipo just burst into flames sitting on the bench or in the flight box
or maybe in a plane or on the charger
I know people have hooked them up to car batterys and filmed the resulting fire but that is not real life
Just wondering if any can share a real life event that they wittnessed first hand and the events the lead up to the fire
thanks
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Old 03-30-2007, 02:15 PM
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orionRider
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Tried to blast an old 3000mah 2S LiPo by shorting it: no joy, it will just balloon a bit.

Then it took 15 minutes at 8Amps constant to explode a 1200 2S pack.

In my opinion, this is the only way to acheive a Lipo fire by accident: charge a lipo on NiMh mode while you're out for the evening. The very low internal resistance will force the charger to high amps and there will never be a delta peak to stop the process. Ultimately it may explode.
But long before that it will become warm, then hot, then balloon, and the display on the charger will not look right from the beginning.

As long as you check the charge process every now and then, there is no danger. At least in my opinion
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Old 03-30-2007, 03:44 PM
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Well, I know Bill has had one.
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Old 04-02-2007, 03:29 AM
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Matt Kirsch
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You've just got to go through the threads to find many instances of LiPoly fires, but you've got to go quite a ways back to find them with any frequency. As time has marched on, fires have become fewer and farther between.

Most of them you'll notice are a direct result of using the wrong charger, using the wrong settings on the charger, severe abuse, or severe crash damage. Bringing the voltage of a cell above 5.2V will cause it to catch fire. Short-circuiting the cell, either externally by touching the wires together, or internally through traumatic cell damage (bend or dent a cell badly enough).

You won't find an instance of a pack just going up sitting there. The pack will have suffered previous damage or abuse. Otherwise, you couldn't ship or store the things.

Last edited by Matt Kirsch; 04-02-2007 at 09:42 PM.
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Old 04-08-2007, 01:48 AM
  #5  
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hello I had a one burst in to flames a few days ago it was in a picoo z I was charging it up with a mains charger instead of useing the hand set and went out the room for 5 mins came back and it was on fire i was lucky it did'nt set the house on fire.I did'nt think out would happen that fast I thought people just exagerated how dangerous they are.the worst thing Iwas only reading about them the night before but you live and learn.
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Old 04-08-2007, 03:09 AM
  #6  
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i had one the other day burst into flames after the prop cut into the cells after a nose down on a delta i was attempting to maiden... luckily for me i had to pee really badly and was able to put the fire out
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Old 04-08-2007, 07:21 AM
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There's two examples right there on what Matt was talking about. Over-charging (I assume) and crash damage. I know of an instance where the crashed battery appeared to be fine with only a small dent, but then caught fire in flight. That was after six months of using it!

Morale of the story, you have to be careful. If you damage a LiPo, consider it gone.

Frank
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Old 04-09-2007, 05:23 AM
  #8  
TimOBrien
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The real deal:

Lithium is a reactive element.
Exposure to water or abusive charging will cause it to react violently.

Is that a problem? Think about how reactive the gasoline in your car tank is (much much more...) Everything is a matter of degress and risks. Heck, you can get poisoning from oxygen or water.

Read the directions, follow the rules and you'll have some fun with your airplanes....
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Old 04-11-2007, 02:42 AM
  #9  
Matt Kirsch
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Define "reactive" with respect to water. I don't think it's reactive in the sense that it catches fire when exposed to water. It's reactive in the sense that when exposed to water, it forms a new chemical compound.
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Old 04-11-2007, 07:54 AM
  #10  
Thunder500
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Sorry to butt in guys but I've been reading a lot of threads on lipos catching fire and its giving me the bumps. Most of the fire incidents occur during charging and I'm not so sure if what i'm doing is right. Any comment can be of great help to me. Everytime I charged lipos I go through the process of balancing it first ( I have a separate balancer and charger) before charging it. Normally a 3s lipo would balance in 10 min before charging. After charging I again do another balancing before finally using it on the plane. I've been doing this for two years now and so far I have no problems with my batteries. It's a long process I know but experience shows that the lipos are still good since I bought them
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Old 04-11-2007, 08:19 AM
  #11  
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Originally Posted by Matt Kirsch View Post
Define "reactive" with respect to water. I don't think it's reactive in the sense that it catches fire when exposed to water. It's reactive in the sense that when exposed to water, it forms a new chemical compound.
Pure Lithium is an extremely reactive element and will react with water to produce Hydrogen gas and generates sufficient temperature to ignite it - drop a piece of Lithium in water and it the gas produced will catch fire.

However, LiPo cells contain no pure Lithium, it is all contained in chemical compounds. LiPo cells should not catch fire if exposed to water, even with the envelope punctured.

The critical factor is the internal temperature. Above a certain temperature a chemical reaction commences, which procuces heat. This heat build up is called "Thermal Runaway" and will often lead to the cell catching fire.

There are only 3 ways to really cause this to occur - Overcharging, damage and overdischarging. Overcharging causes the internal temperature to rise above the critical point. Damage, where critical, causes an internal short circuit locally causiing the temperature to rise above the critical point.

Overdischarging is highly unlikely to cause the cells to catch fire but could in extremis. It would have to be coupled with currents at or beyond the cell rating; normally it just leads to a dead cell.

Interestingly I had 2 Kokam 1250 packs puff up this winter just sat in the garage. They were both charged and not connected to anything, they just puffed up for no known reason.
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Old 04-11-2007, 11:25 AM
  #12  
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The short answer is yes, I had one catch on fire in 2004. The pack had been charged with correct settings. The pack was sitting on the passenger seat and caught fire. Why? I don't know. It was unlikely that it touched something metal. It was summer in Florida (ie high temps), but the packs had only been in the car for 20-30 minutes. The matching pack had puffed with less than 10 cycles. Was there an internal fault? I don't know.


I fly quite a bit and I belong to two clubs. I was the only one that had a pack catch fire for no apparent reason. There were only a couple of other fires that were traced to improper charging or trying to charge a damaged pack. We have had no incidents in at least two years now. Our biggest problem now is the old silver sausage.


John
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Old 04-11-2007, 11:27 AM
  #13  
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Originally Posted by jonnyjetprop View Post
The short answer is yes, I had one catch on fire in 2004.

John

How about some details?
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Old 04-11-2007, 03:41 PM
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Murocflyer
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Originally Posted by Thunder500 View Post
Sorry to butt in guys but I've been reading a lot of threads on lipos catching fire and its giving me the bumps. Most of the fire incidents occur during charging and I'm not so sure if what i'm doing is right. Any comment can be of great help to me. Everytime I charged lipos I go through the process of balancing it first ( I have a separate balancer and charger) before charging it. Normally a 3s lipo would balance in 10 min before charging. After charging I again do another balancing before finally using it on the plane. I've been doing this for two years now and so far I have no problems with my batteries. It's a long process I know but experience shows that the lipos are still good since I bought them

Thunder,

How can anyone say your procedure is wrong if its worked for two years? You must be doing something right!

I'd like to hear some comments on the above. Seems like he's good to go. The only thing I know about balancing LiPos is that my FMA Cellpro balances my batteries when charging them. Other than that, I'm embarrassed to say I don't know much more. Give me some time and I can find the answers for you, but I know not everyone uses a charger that balances their LiPos also. Looking forward to those guys chiming in.

Frank
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Old 04-12-2007, 11:25 PM
  #15  
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Originally Posted by jbassett View Post
How about some details?

There are no other details than what was posted. Pack was recharged in the car on the way home from the field. All was normal with the charge. When the charge was complete, the pack was disconnected and placed on top of the passenger seat. I got home, stored most of my stuff but left some of it in the car, including the batteries that had been charged. Come back out after 20 or so minutes and car was burned out. The pack caught the seat on fire, which caused the car to catch on fire. It put itself out after consuming all the air inside the car.

John
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Old 04-19-2007, 12:26 PM
  #16  
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Pack was recharged in the car on the way home from the field.
I see some potential causes here.

When the engine runs, the electric circuit of your car can deliver 15+ volts instead of the nominal 12v. A very basic charger could be fooled by the higher voltage.
While driving, you can't check the amps and voltage during the charge. Maybe the pack was already too hot, from charging and from the sun.

In 2004, the LiPos were low 'C' and probably more prone to thermal runaway than the current high discharge batteries.
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Old 04-19-2007, 01:28 PM
  #17  
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Originally Posted by Murocflyer View Post
Thunder,

I'd like to hear some comments on the above. Seems like he's good to go. The only thing I know about balancing LiPos is that my FMA Cellpro balances my batteries when charging them. Other than that, I'm embarrassed to say I don't know much more. Give me some time and I can find the answers for you, but I know not everyone uses a charger that balances their LiPos also. Looking forward to those guys chiming in.

Frank
Some basics here:

http://www.ampaviators.com/index.php...d=58&Itemid=27
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Old 04-21-2007, 05:43 PM
  #18  
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I have 3 lipos now and I am just getting into this balancing act. So far no troubles with the lipo’s but this thread reminded of a nicad incident a few years ago. I agree that if you have a fire problem it will be during the charging process. I was charging a six pack in the front room on the fire place hearth one day. Blam ! It blew two of the six cells apart and discharged hot metal shavings onto my carpet. I was in the doghouse for quite awhile after that little escapade.

I have puffed a nicad pack before. Only bad karma can come from a puffed pack. Haven’t puffed a lipo, . . . yet. I am thinking I want to get a hold of a lipo that I don’t care about and play a little mythbusters on it. Right now I am living dangerously and just charging under the hood. Sometimes I even carry them in my pocket while at the field. I hope I get into more safe processes before I burn something up.

Last edited by mikeyv; 04-21-2007 at 05:48 PM. Reason: syntax
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Old 04-22-2007, 06:49 PM
  #19  
Spencer J
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I popped open a 2S Kokam 2000mah 15C battery while landing my Slow Stick (rubber band mount for the battery came off) and I tossed it on ashphalt, expect it to burst in a matter of a few minutes. Well a half an hour passed, and....nothing. I left it in the middle of my driveway over night and....nothing. It rained that night too, so it was in a puddle. The next day I shot some photos of it. Then I took a hockey stick to it and beat the heck out of it. The pack started to curl, but nothing happened. I then followed the procedure of disposing of a Lipo pack...let it rinse in a bowl of salt water for an hour, then cut it up and throw away.

Throughout the entire process, the worse that happened was the pack curled.

That same day I blew a hole in another kokam battery I had (Same type, bought at the same time) during charging. The pack had received great care, and I think it died because the cells were out of balance (There were no balance taps) worried that my remaining two Kokam batteries would break, I sold both of them 'as is' the following day on ebay for $24.

Personally, this whole LiPo bam-bam thing is something for big hobby business to take advantage of. Unless if you charge yoru pack at a very high rate (Like 15C+) it will probably blow, but if you are careful you should be just fine.
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Old 04-22-2007, 11:10 PM
  #20  
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ehobby-rc, I'm sure what you were doing could potentially have blown it or something, but yeah I have always thought this was badly overblown and agree with you on it being a nice little niche business with anti lipo-fire bags and cannisters and all that, it's really an overblown fear.
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Old 04-23-2007, 02:44 AM
  #21  
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Hi All,

Whereas I have not had any problems charging my batteries, I did have a pretty severe crash of my Falcon 56 in which I was running a CC 60A ESC, E-Flight power 46 and a 4000ma 4S lipo. I was having all sorts of radio issues about 15 seconds into the flight and so I decided to get it back on the ground pronto, but I lost all control on final and it went in from about 100' and 2/3 throttle. I *think* it was a crystal issue, but I'm not sure. Anyway, the airplane suffered surprisingly little damage, but just seconds after the crash, white smoke started billowing out of the fuselage... No actual flames that we could see, but that pack was hot for a couple hours afterwards. Here are some photos... I actually think the airframe is reparable... It looks really bad, but a lot of the black is cooked foam. The wing split the covering and the tail came off cleanly in one piece... Anyway, this is the other danger... Even if you are completely safe with the care of your batteries, a bad crash (and I think it was actually a short and not physical damage) can cause a fire on the ground.

Bummers,

Franny
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Old 04-23-2007, 04:24 PM
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The charger was not being powered by the car's electrical system. I was using a seperate car battery. I charged while driving because I could monitor the charge. It was easy to look over and check. Trust me, I was running the ac while driving.

John


Originally Posted by orionRider View Post
I see some potential causes here.

When the engine runs, the electric circuit of your car can deliver 15+ volts instead of the nominal 12v. A very basic charger could be fooled by the higher voltage.
While driving, you can't check the amps and voltage during the charge. Maybe the pack was already too hot, from charging and from the sun.

In 2004, the LiPos were low 'C' and probably more prone to thermal runaway than the current high discharge batteries.
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