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HomeAircraftHelicopterMain Discussion › Lipo volatility myth or fact?
10-09-2012 11:38 AM  5 years agoPost 41
Ronald Thomas

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Gainesville, Fl, USA

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I just had (2) bad 3s packs. I intentionally drove a nail through both of them, got smoke but no fire. IDO think they are dangerous though if you don't care of them......Ron

Team MikadoUSA 480XXTreme, 550SX, 600SX, 700XXTreme, 800XXTreme!!

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10-09-2012 02:16 PM  5 years agoPost 42
kruuuzn

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Traverse City, MI

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Does anyone have first hand knowledge of an unvented ammo blowing up?

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10-09-2012 02:41 PM  5 years agoPost 43
davehour

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Guayama, Puerto Rico 00785

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I store my batteries at storage voltage in the fridge. Comments are welcome

Another area of great concern in electrics is parallel charging. Very convenient if done right; real bad if done wrong.

I think "Education" is a key factor to anyone in electrics.

David

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10-09-2012 02:42 PM  5 years agoPost 44
Cra-Z-1

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Washington,UT-USA

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The applications you mention are designed with more safety, and less power to weight, than what is used in RC. This is a common misconception...that RC batteries are as safe as home electronics. Simply not so...not by a large margin.
Also, there was an issue with some laptops a few years back and it resulted in a big recall. An electric car has caught fire and caused great concern...I think the Chevy Volt was taken off the market. It seems the failure rate has to go much higher for this to happen with RC. RC needs to be treated with much greater care.
More safety? How did you draw this conclusion? Less power to weight? It doesnt take much "power" to create a fire, or for a lipo to reach it's thermal runaway state. Whether its a very small lipo or a large one, it will create a fire very easily. Lithium ION, which is used more abundantly, is also a more volatile mixture, from what I have read on it, in the past. Why would you assume that RC batteries are NOT a safe as home electronics? Do you think they are made in entirely different manufacturing plants? I think that the level of safeness, is dependent on the condition of the pack, and the responsibility of the user to charge/treat the battery correctly. I too, have tried to create a lipo fire by shorting the cells via puncturing them. I've been unsuccessful so far. The Chevy volt was taken off the market; true, but not because of electrical issues. Each car cost $90,000 to manufacture, and they are selling them at only $40,000. I do agree that RC needs to be treated with greater care, but because of the environment they are prone to see, such as crashes, vibrations, etc...

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10-09-2012 03:09 PM  5 years agoPost 45
Four Stroker

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Atlanta

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The Chevy Volt was a scam to get the bail out money. They never indended to sell it in volume.

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10-09-2012 03:26 PM  5 years agoPost 46
Rogman88

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West Monroe, LA

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I crumpled a pair of turnigy 3A 6S packs in october 2010. Buddy said they were toast and to get rid of them. I still have them and have put another 100 cycles on them. They are weak and tired but can still get the heli up for some auto practice.

High Voltage just works better

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10-09-2012 03:27 PM  5 years agoPost 47
GetToDaChopper

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Las Vegas , NV

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It had nothing to do with "bail out money".......

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10-09-2012 04:08 PM  5 years agoPost 48
Solmanbandit

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Tucson , AZ

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Li-ion batteries contain safety devices that, protect the cells inside from abuse. If damaged, these can cause the battery to ignite or explode.

Trex 700E / Trex 500 ESP - Ikon/ HD 500 - Ikon 2/ Goblin 500 Ikon 2

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10-09-2012 04:15 PM  5 years agoPost 49
Solmanbandit

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Tucson , AZ

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Each car cost $90,000 to manufacture, and they are selling them at only $40,000. I do agree that RC needs to be treated with greater care, but because of the environment they are prone to see, such as crashes, vibrations, etc...
“Nearly two years after the introduction of the path-breaking plug-in hybrid, GM is still losing as much as $49,000 on each Volt it builds, according to estimates provided to Reuters by industry analysts and manufacturing experts,” the news agency reports.
http://blog.heritage.org/2012/09/10...ggering-losses/
Apparently this is the real answer. It is a good question as to why they would produce it in the first place at a loss.

Trex 700E / Trex 500 ESP - Ikon/ HD 500 - Ikon 2/ Goblin 500 Ikon 2

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10-09-2012 05:01 PM  5 years agoPost 50
deafheliflyer

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Arizona

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Lets stay on topic, folks..

Lipo and safety as it pertains to R/C helicopters..

Thank you!!!

Michael

Crash-Prone and overcoming it!!!

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10-09-2012 06:55 PM  5 years agoPost 51
BobOD

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New York- USA

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How did you draw this conclusion?
1. Design
From an understanding of the vastly different safety measures used in batteries for laptops and other consumer devices. For example, many cells are encased in steel tubes. This is protection for the internals and they are also designed to control venting. These cells are almost always encased in a hard plastic cover for further protection. Also, there are built in protection circuits which RC does not have. Even cell phone flat packs have metal enclosures under the plastic outer wrap (although the small amount of energy in these is much less likely to cause a fire). All this results in more weight...so lower power to weight.

2. Observation
I've seen far more helis come flaming from the sky than laptops.
Also, I do not have statistics but there have been electric cars catching fire as well. I beleive a much higher incident rate than a gasoline powered car. And, there are a LOT more safety measures in these batterias than RC batteries.

3. Lack of Safety Net
Has anyone ever seen a recall of RC batteries? We saw Castle voluntarily recall ESC's after a year of widespread fires. By contrast, many of you don't even know about recalls of laptop batteries due to a few fires. That's because the problem was identified and addressed quickly.

RC batteries need to be treated with much more care than those in other markets.

Team POP Secret

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10-09-2012 08:50 PM  5 years agoPost 52
Cra-Z-1

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Washington,UT-USA

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So going back to the OP's Original question...."Lipo volatility a myth or fact?"

I think that Lithium Polymer chemistry is a actually a pretty safe chemistry to use. Do I think a Polymer battery will spontaneously combust undamaged and unprovoked? I say no, provided that they arent stored where they are exposed to significant heat. I still think that a short further upstream has to occur that can generate a significant amount of heat, for a fire to occur. Then once enough heat is generated, the lithium material will indeed ignite and burn. I think the best medicine is to take care of your batteries, and they will take care of you. Any chemistry that can generate enough electrons to produce hundreds of amps, is going to create a fire easily. Probably the reason our RC batteries dont have better safety measures like you mention to prevent thermal runaway, is because often times we demand peak power from them, vs. longevity, such as a Laptop...phone...etc. I've taken apart those little keychain cameras, and Ipods, and indeed their lithium polymer packs are NOT protected by any external jacketing. They look just like a miniature sized RC lipo, with a foil-like jacket.

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10-09-2012 09:51 PM  5 years agoPost 53
BobOD

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New York- USA

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Cra-z-1,
You are not disagreeing with what I'm saying really. Just making a different point.
And my point is that most consumer electronics are designed with more safety than RC ones. And, this includes the prevention of abuse....this makes them more safe. And this is why the incident rate is far lower in those markets.
With RC, you need to be more aware yourself in order to be safe. One simple example is having a user applied plug on a device capable of producing hundreds of amps. This would not be tollerated with consumer electronics. In fact, it would be nuts to leave such a thing lying around the house.

Regarding the smaller batteries. No, they are not as likely to start a significant fire. So, they require less safety measures. Even still, the batteries in ipods and cell phones have more safety measures employed than in RC. The "foil" is typically thicker, they are installed in more protected environment, have electronic safety circuits to avoid abuse of the battery and they are put under less demand or less abuse and no exposed wires. Sure they can start a fire...just much less likely. In some cases, the state of charge is limited to less than 100% Sometimes they are limited to being charged up to only 80% of what they could be. One reason is for safety. A Lipo only charged to 80% capacity has been deemed a lower risk. The designers provide safety rather than leaving it to the consumer. Yes, you may wish to charge to 100% for your application, just be aware that this increases the risks. You may want to discharge at high c rates...etc

There is no myth about whether lipo powered helis start fires. They start fires in the heli during operation, they start them on the charger and they start them just sitting there sometimes hours after the actual "abuse" that caused it. It's important to know what the causes are but this has nothing at all to do with the fact that their volitility is no myth.

Now, I am not saying all this is wrong or whether it should be changed. This is not for me to say. All I'm saying is that they are not the same as your laptop batteries and unless treated with much more responsibility, can be quite dangerous.

Team POP Secret

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10-09-2012 10:33 PM  5 years agoPost 54
Ace Dude

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USA

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Has anyone ever seen a recall of RC batteries?
I doubt few resellers in this industry could afford to implement a recall. There's not enough markup to repair or replace a pack with even a small number of pack affected.

  

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10-09-2012 10:35 PM  5 years agoPost 55
Ace Dude

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USA

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Regarding the smaller batteries. No, they are not as likely to start a significant fire.
You only need a small spark to start a fire. After that could easily spread causing significant damage.

  

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10-09-2012 10:45 PM  5 years agoPost 56
Cra-Z-1

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Washington,UT-USA

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You are not disagreeing with what I'm saying really. Just making a different point.
Right...but what I was getting at, is that the chemical mixture of lithium polymer batteries is no more volatile than the lithium Ion counterparts that we use every day from shavers, to laptops, auto's, and beyond...its not something that is just going to explode or go to thermal runaway state without being provoked to do so; i.e. just sitting in a storage bin.

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10-09-2012 10:45 PM  5 years agoPost 57
BobOD

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New York- USA

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That doesn't change the fact that a smaller pack takes less to contain.
Are you saying a big 6s 5000mah 65c pack does not have more potential to start a fire than a little 1s 1000mah 0.5c?

Team POP Secret

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10-09-2012 11:00 PM  5 years agoPost 58
Cra-Z-1

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Washington,UT-USA

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That doesn't change the fact that a smaller pack takes less to contain.
Are you saying a big 6s 5000mah 65c pack does not have more potential to start a fire than a little 1s 1000mah 0.5c?
0.5C? lol....not likely at 500mA...what burst rating??? lol, but if it managed to start smoldering, thats all it would need. It would just take more time to get going.

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10-09-2012 11:11 PM  5 years agoPost 59
BobOD

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New York- USA

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its not something that is just going to explode or go to thermal runaway state without being provoked to do so; i.e. just sitting in a storage bin.
If it has been provoked, then it could. In fact, this sort of thing does happen. They are "provoked" quite often. I know what you are saying. Don't provoke them. I agree. This is because they are not safe if provoked. This does not change the fact that people are provoking them....and they are catching fire. How about the incidents where there was a crash that caught the field on fire? What is your recommendation to prevent this provocation?

Look at the evedence right here in this thread. I know a guy who dropped his pack. Put a tiny little ding in the corner of it. Hours later it went up. He's lucky he was around. I don't think I would have said he needs to throw that pack out. Now, I raise the question because it is not clear.
Then look at the post above about packs that were "crumpled" and he is still using them. Was he wrong? I know Rog, he is intellegent and well informed but took a risk because no-one has clearly defined what is acceptable and what is not.

There was also a thread a few weeks back where a guy was hovering with a brand new pack and the battery lit up. Looked like it was a defective battery. You just don't see this with consumer electronics.

A stick of dynamite is safe when used properly. How could you say it is therefore not volitile?

Team POP Secret

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10-09-2012 11:24 PM  5 years agoPost 60
Cra-Z-1

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Washington,UT-USA

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How could you say it is therefore not volitile?
Lol.....I'm not. I'm saying they are no more "volatile" than all the other batteries that your electronics are running off of. All of the instances you gave, were instances that were "caused" by the way they were used. I'm saying they arent just going to catch on fire and burn without a reason, and I still doubt those instances in which your examples gave, was due solely to the pack itself being damaged, versus a short created from the circuitry that joins the packs together, and causing a high current load. Those packs consist of many laminations of lithium, and therefore, each layer's power capability is limited. That in itself is the reason you can literally stab a pack with a knife, and it wont explode on you.

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HomeAircraftHelicopterMain Discussion › Lipo volatility myth or fact?
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