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Old Aug 13, 2003, 01:05 PM
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Dave H: You need to read the other thread "LiPo Fire Pictures" toward the end of page 2 you will see a post by Big Dave on his LiPo house fire.

"I had a Li pack explode while charging and shoot itself off of my charging bench. the pack landed on CARPET in my hobby room and started a fire. The resulting damage to my house was limited as my fire alarm system went off and, luckily, I was there. A fire extinguisher stopped this from turning into a major disaster (like the vehicle in this posting). Several planes and kits went up in smoke. Lots of repairs to the home were required BUT it could have been worse"

"ALWAYS charge Li packs in a fire proof contatiner with a LID. If the pack ruptures it will ROCKET off of any fireproof surface and jet off to some other area. This is a cheap lesson for those reading this post."

And yes there is a picture of the pack and the cells were LiPo's.

Now I have lost count, but I seem to remember:

- garage and contents burned out
- kitchen burned out
- SUV burned to the ground
- hobby room damaged
- passenger seat of a BMW burned beyond repair

And this is with the product only in use for RC for about one year.

You were right on the mark with:

" If I were earning my living selling LiPo cells and chargers right now, I'd be extremely concerned."

Brad
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Old Aug 13, 2003, 02:57 PM
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Dave H.
Checked with the vendor about the pack. It was a 2 cell 2100mah. Sorry I was wrong about the mah, but the cell didn't last long enough for me to be able to read you the lable. Also sorry that I shower of sparks was unknown to you in the past, but I didn't make it up!
Any attempt to diminish the potential problems with these cells is misguided and should not be distributed as "gospel." I only make the point that we need to be aware and the mfg's and vendors owe us a more responsible method of making us aware of the potential for disaster.
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Old Aug 13, 2003, 03:07 PM
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I aree with Dimberio. These things are to be treated with respect, not fear. And the vendors/manufacturers are best served by being direct about the issues and proper handling.

For example, I replaced my Schulze with a Triton (was on my LHS shelf) and the Triton carries many warnings about LiPo charging and use, unlike what we've seen from some pack vendors.

Ken
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Old Aug 13, 2003, 03:20 PM
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So far this thread has concentrated on lipo battery accidents on the ground.

Whilst reading the 200/lb Pattern Plane thread on the sport forum I came across the photo below. From what it says on the thread - go to this page

http://www.rcgroups.com/forums/showt...5&pagenumber=5

and scroll down 'till you reach the photo, caption and subsequent posts - the high-power FAI pattern ship caught fire during an aerobatic training flight.

Edit: on re-reading the post, all that was said was that the problem occurred in the air. No definition of "problem". What we're seeing here is the result. More probing might get the full story.

Gordon
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Old Aug 13, 2003, 04:22 PM
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Quote:
Originally posted by bjpaul
Now I have lost count, but I seem to remember:

- garage and contents burned out
- kitchen burned out
- SUV burned to the ground
- hobby room damaged
- passenger seat of a BMW burned beyond repair

Brad
There was another car burned to the ground.

This is about as well said as possible:

"Any attempt to diminish the potential problems with these cells is misguided and should not be distributed as "gospel." I only make the point that we need to be aware and the mfg's and vendors owe us a more responsible method of making us aware of the potential for disaster." dimberio

hoppy
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Old Aug 13, 2003, 05:21 PM
MKH
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As I see it, I can monitor the charging of my packs, and can store them safely when not in use. This leaves internal damage as my main concern, and a nerve-wracking drive home after a crash. I love these cells, but if crash-damaged packs continue to burn up for people, I may have to reconsider my choices. I can't risk my car or house or health for the sake of flight duration. I don't consider this an alarmist position, just a cautious one. Personally, I don't care if it melts, explodes, burns, ignites, or whatever word you want to get hung up on. The accident reports I've seen seem to come from people who are/were big fans of lipos, and have no personal grudge against these cells. I appreciate those of you who are trying so hard to get to the bottom of this. Right now, the risks look very real, but manageable. Time will tell, hopefully without anyone getting hurt. I keep going back to the main draw of lipos, namely, that they have the highest energy density of any cell we can use. It would appear that this very selling point can also bite us hard.
Marcus
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Old Aug 13, 2003, 06:30 PM
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Marcus,
I dumped mine because I personally felt the risks outweighed the advantages! I have made it 76 years and some of the risks I have taken in the past now scare me to death thinking about them! Maybe my age! "too soon old and too late smart!" It comes down to a personal decision for each of us! I can't see how a failsafe system could be designed to minimize the risks as any device to interrupt the power output would have no effect on a crash related damaged cell and any device that cuts off the power if a problem occured during flight would produce an unguided missile! One post stated he had made a foam lined box to prevent crash damage but this adds weight and generates other problems! Any great ideas out there????? I would buy a bunch in a minute if the problems could be solved!
boomer
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Old Aug 13, 2003, 06:33 PM
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dimberio said:
...I will admit that my charger (one that is supposed to correctly charge lipo's) incorrectly put in more amps and created a problem...

Just some questions for clarity:
What charger were you using?
How many amps was being put into the 2100mAh LiPo's?

Regards,
Pieter
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Old Aug 13, 2003, 07:11 PM
MKH
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I hear you Boomer. If your nimhs and nicads do the job, thats fine. I use lipos in IFOs and similar planes, in close, pretty slow, no spectators around, all fellow flyers educated about lipos. I feel fine with that. Like you, I examine my past, and find examples of flying that would scare me if lipos were onboard. I've lost sailplanes to thermals and radio problems, and recovered them blocks away, badly damaged. I've also cartwheeled 6 pound sportplanes and had them come apart in spectacular ways. 2 midairs to my credit, too. If lipos are indeed more likely to have problems from crash damage, I'd be much less likely to want them in these planes. For now, slowflyers and parkflyers are all I'm flying, so I don't need to reach any final conclusions now. I'll keep up with these threads, and see how we do. I will not, however, charge my packs in a fire pit, store them in a vault, or stand by my charger with a fire bottle. If it comes to that, I'll go back to nimhs and nicads. I hope it doesn't come to that.
Marcus
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Old Aug 13, 2003, 10:01 PM
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I've been flying with various lithium cells for 3 years now without a single problem. As with other lithium cell users, I have a vested interest in understanding as much factual information as possible about any lithium cell failures inasmuch as my home and my family are at risk should something go wrong.

Is there anyone here who is not interested in getting the most factual data possible about every lithium cell incident so that they can make rational decisions on appropriate measures to ensure the greatest safety for all?
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Old Aug 13, 2003, 10:11 PM
DNA
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"Dimberio, your story is unique in that it is the first firsthand description I can recall of a LiPo pack that "exploded showering sparks in a 20 foot circle."

Dave H: You need to read the other thread "LiPo Fire Pictures" toward the end of page 2 you will see a post by Big Dave on his LiPo house fire.


And Dave H, I know for certain that you read this post as it was a reference to your... 'I never heard of a lipo cell going "boom" when they ruptured'. This post clearly states it "showered glowing embers all over the garage wall". So Dimberio's post is neither unigue nor the first description of showering sparks.

"BTW: I had a Kokam 1020 2 cell li-poly blow up on me as well. I was using the Triton charger. I idiotically left it unattended when I starting watching a TV show. Heard a boom in the garage. Ran out there to see my desk on fire. I grabbed a towel and quickly scooped the whole mess up and chucked it on the driveway. When it blew it showered glowing embers all over the garage wall and surrounding area."

Although it didn't cause a fire (but could have), this is the first instance of a lipo rupturing that I can recall. It was posted Aug. 31, 2002 and was caused by shorting some Ultralife lipos.
http://www.rcgroups.com/forums/showt...threadid=59306

hoppy was partly correct about there being another car (orlando) (I have the picture) that was burnt to the ground while charging some lipos inside the car. There was also a third car fire that was caused by the C750 dedicated lipo car charger being sold by BPP.
http://www.rcgroups.com/forums/showt...highlight=c750

The really bad part about all this is that we're only hearing some of the stories of Ezone members who have had fires involved with lipos. I've read that 80% of modelers aren't members of internet forums. Surely some of them must be using lipos as well, that we're not hearing about. You can be certain that the insurance companies and fire departments are gathering statistics about what is causing fire damage claims.
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Last edited by DNA; Aug 13, 2003 at 10:14 PM.
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Old Aug 13, 2003, 10:31 PM
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Mork,
The charger was a Shulze. It had the software versopm previous to the one that is now been updated (Version 8) I bought my charger from the US distributor apparently just a month or so before the ones with the updated version.
I must say the US distributor was not much help. They refered me to Shulze in Germany where I ended up sending my charred charger for repair and updating.
I don't know how many amps were being put in as it was supposed to function automatically.
I verified the programming and socket set used with a collegue who has used this charger successfully in the past. While I am not stupid, I felt unsure about the instructions which seemed to suffer from translation from German to English. The "booklet" I received from the US distributor was a photocopy of dubious quality. When I asked for a replacement as the one they sent was also charred, they told me to go to the mfgs site and download it. Can't say much about their service (US distributor)on a technically tricky product which I passed on to Shulze.
I feel as though I did all I could to do it right, but still ended up with trouble. That is why I will stay away from LiPo's for the present untill there is more clarification regarding safe and unsafe proceedures. All other charging proceedures on NiCads and NiMh cells have gone off without a hitch.
I do not ascribe any blame anywhere except to myself for going into something about which I did not know enough.
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Old Aug 13, 2003, 11:15 PM
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Martin,
No do not use a bloated cell. It bloated from overcharging. Please continue to research their use more before continuing.
-Mike
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Old Aug 14, 2003, 07:40 AM
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Thanks Dimberio for getting back to my question in the thread. I am fairly sure your incident was due to hugely excessive charge current.

My brother and I have been using LiIon (out of mobiles or cell phones) for just over 18 months and the closest either of us have come was swelling a cell. Len swelled two, I swelled one but that was all. In both cases we beleive we discharged them too deeply. Upon charge (or during it) they presented a short circuit. We use home built chargers and current limit charge to under 1 Amp (1C). I think that what saved us is that limiting current limited temperature so the cells did not get hot enough to burn by themselves. In fact we could still handle them comfortably.

The next nearest we came to disaster was when Len shorted a cell. It got very hot very quickly. He moved fast, ripping the short off and throwing the cells outside. Thankfully they cooled down rather than burned. No damage done either, he was able to keep on using them.

Based on the experience of others that we read on the E-Zone in the past year my brother has been charging his cells in a ceramic pot and we both use Micro Deans connectors so the ends can not touch. Reading this thread we reckon it is time to make up a carry box that packs the cells so they are protected and kept separate. Based on your experience I am also planning to put a 1 Amp slow blow fuse in line with the output of my charger in case someting goes wrong with the charger.

We got our first LiPo in April and are even more chuffed with them. I am fairly sure LiIon is okay to use so long as you do your reasearch carefully and stay informed, treat them with respect, be conservative on charging and keep a healthy attitude of paranoia.

For LiPo the above applies with the advantage that swelling is less likely to result in a "bang".

(The charger Len and I use is similar to the design on http://www.shdesigns.org/lionchg.html )
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Old Aug 14, 2003, 08:54 AM
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Quote:
Originally posted by dimberio
I will admit that my charger (one that is supposed to correctly charge lipo's) incorrectly put in more amps
Did you happen to see how many amps were being delivered to the battery?

hoppy
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