Lipo fire 5S2P - add me to the careless list - RC Groups
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Mar 09, 2006, 01:23 PM
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Larry3215's Avatar
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Lipo fire 5S2P - add me to the careless list


I had a lipo fire last night charging a 5S2P 4000 pack for the first time.

After checking things out and re-living last night many many times - I am quite certain the pack was NOT at fault.

At first I thought the pack had to have gone out of balance, but after I got the power back on to the charger I found it was reading 25.0 volts instead of the 20.5 I was certain I had it set too.

Either I set it wrong to begin with or the charger malfunctioned. There is a small chance the heat from the fire or the fire extinguisher messed up the setting on the supply, but I doubt that.

I normally under charge to a small degree. I am still 95% certin I had it set o 20.5 volts - my normal 5S setting. I looked at the charger several times durring the charge and even stopped and re-started the charge to check fit in the plane and balance adaptor wireing.

Maybe I went dyslexic and set it to 25.0 by mistake.

That cccv supply has a history of creaping up about .1 volts durring a charge session, so I am suspitious of a charger failure.

I would prefer to believe it was equipment failure rather than my stupidity/carelessness. Sense I cant prove either one - Im going to blame the equipment.

Im bummed. Major damage to 4 planes, TX is toast, CCCV supply, Fluke meter, tons of mis gear.

Almost ALL my other lipos were in an open container next to the fire and are probably trash too. They are covered in soot and fire extinguisher dust and got really hot.

On the good side - no injurys and no fire damage to the house. Lots of smoke damage tho.


I did some things right and several things WRONG.

I'll go over those more later.

I'll just mention one of the right ones for now - I had a fire extinguisher by the work room door. I used an ABC dry chemical extinguisher that did a great job of controlling the fire - even durring the event while it was still venting.

More later.

Larry
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Mar 09, 2006, 01:43 PM
Registered User
Larry,

I charge LiPos when graphing @ 4.202 volts. I've accidentally charged at 4.220, so I know the feeling.

But as luck would have it, that particular number reversal doesn't cause a fire.

- RD
Mar 09, 2006, 02:16 PM
Southern Pride
everydayflyer's Avatar
The sadest part is that a $40 Hyperion LBA 6 would (most likely)have prevented this even if the power supply was set to 25 volts by mistake or changed on its own.

Added most likely as nothing is 100% however during my testing of forced over charges it has always worked.

Charles
Last edited by everydayflyer; Mar 09, 2006 at 02:39 PM.
Mar 09, 2006, 02:50 PM
Registered User
Given that the fairest argument against your concerns about the safety of the inexpensive Graupner charger in the-world's-longest-thread was that simple human error or carelessness in the use of more exotic chargers is probably more dangerous than the what-me-worry Graupner...............I salute you for volunteering the particulars of this incident.

-- Mike
Mar 09, 2006, 05:08 PM
Registered User
I think that the very old truth is, " if anything can go wrong, it will". There are some reasons to use renundancy in critical things like Lipo voltage is. I have renundancy and I allways prefer it while talking or writing about Lipos and cell voltages.
I guess that PSU overheat can be reason as You mentioned that it rised voltage before this last time, and higher current or voltage than previously used with smaller pack could lead to overvoltage? But it is not important.
Once the charger fails, cell protective circuit have to disconnect it. Once cell protection fails, charger will not give more voltage (I am afraid of balancer that can fail that way, that sinfle fet will bleed single cell, resultng in other cells overcharge). In addition every situation in pack cells have to be covered by protective circuit (allmost open or shorted cell). In addition, user can fail too, so charger can be set to wrong voltage or protective circuit (or any of wires from pack) can be disconencted.
Solving situation where two or more things will fail at once is too complex for me to try.
Last thing I am to mention is, that I allways do balance of new or longer time stored pack, I will keep in mind suggestion to use balancer with new pack at very first charge.

We, every people, are careless. Some from not understanding the danger, but others become careless after they have enough experiences and knowledge that they stop feeling the fear and stop considering that dangers are serious. This takes place everywhere, including fast driving cars or crossing the street..
I can only repeat that I am sorry for what happened to You.
Mar 09, 2006, 09:03 PM
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Larry3215's Avatar
Hmmmmm

I just checked the pack. It is reading .6 volts

BUT....

It is still warm!!!!!!

It's been outside in the yard in near freezing temps all night and all day (its snowing outside now and has been most of the day) and I can still feel warmth without even touching it. Put my hand just above the pack and I can feel the heat.

The insurance adjuster wants to see it - he is coming tomorrow. I am afraid to touch or move it again. Its still sitting in the Brinks box as in the pic above out in my yard.

After he gets a look at it, I think I will add salt water to the box, then let it soak a few days, then get a pitch fork and start poking holes.

Back to cleaning up...

The fire extinguisher has done as much damage as the fire it seems like...

Larry
Mar 09, 2006, 09:10 PM
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Larry3215's Avatar
Quote:
Originally Posted by everydayflyer
The sadest part is that a $40 Hyperion LBA 6 would (most likely)have prevented this even if the power supply was set to 25 volts by mistake or changed on its own.

Added most likely as nothing is 100% however during my testing of forced over charges it has always worked.

Charles
Quit true.

Whats worse is I HAVE a TP205 and I elected NOT to use it on this first charge. It would have sounded an alarm that I would have heard well before the fire started.

This brand new pack arrived pretty much in balance at 3.97 - 3.98 volts per cell or so.

I decided to see if (how well) it would stay in balance - on its own - when fully charged.

My intention was to charge it to 20.5 volts and THEN conect the TP205 and see how the pack was doing balance wise.

(sigh)

Lesson learned the hard way - never again.

Larry
Mar 09, 2006, 10:18 PM
Registered User
This reminds me of an old story: If you put an infinite number of monkeys in front of an infinite number of typewriters for an infinite amount of time, one will eventually write Macbeth.

The new take on the old story is that if you put an infinite number of RCGroups members in front of an infinite number of charging LiPos for an infinite amount of time, all of them will eventually experience fires.

It really is sad to see longtime forum members who know LiPos so well proving one by one what we all know: All humans make mistakes, and LiPos are unforgiving of human error.

Larry, I'm sorry to hear that you are the latest to join the list. But I'm pleased to know that you are safe, and that your property loss is minimal. It could be far, far worse, and it eventually will be for some poor soul.
Mar 09, 2006, 11:46 PM
Space Coast USA
hoppy's Avatar
Thanks for posting your experience Larry. Inputs like yours keep me on my toes as I think about experiences like yours every time I'm tempted to just plug in the lipo and walk away (which happens quite often after 2 years without a problem). Your candid report hopefully may prevent other accidents from occurring.
Mar 09, 2006, 11:50 PM
Frankenstein recycled packs
rampman's Avatar
Good you did not add water to the fire extinguisher powder. Hint, don't use water 'till the very last wipes.
Find an air compressor, mask EVERYTHING outside of that room and even things inside there if not too dusty, and blow away to an open window. Shop vac's work good for the heavy areas too. Keep a mask on at all times, that stuff is nasty. Chances are your insurance co will pay a company to clean up the mess... and IF there are motors in the aircraft, remove them before he/she shows up. They may not cover the planes as they have a motor BUT if it is just the plane...

You got lucky as your fire was very contained.
Be careful what you tell the insurance adjuster. You are probably best to say you set the V wrong. Otherwise they will go after the CCCV or CSRC people to pay for your damage. I know, I lost a house 2 years ago and they went after the kid that "maybe" disposed a cig incorrectly for 400k +. Long story...

Keep us posted.
Rick
Mar 10, 2006, 01:57 AM
Permanently Banned
Larry3215's Avatar
Thanks to all of you for the kind words and simpathy.

Rick - Thanks for those tips on cleaning up. Ive havnt had time yet to lok up any details on cleaning. The cleaning company rep came by today, but seemed a little over whelmed by all the little bits and pieces and the planes.

Adjuster is due in tomorrow. I intend to take full blame. The pack was difinately NOT to blame. As much as I hate to admit it, Im almost certain I set the charger to the wrong voltage. 20.5 vrs 25.0 is just to easy an error to make.

Things I did WRONG - in no particular order.
0)set the wrong voltage on the charger
1) Started charging while I had my mind on several other things at once.
2) did not use safty devices that were on hand - TP205 in particular.
3) did not have the pack fully contained in the fire proof box
4) had other lipos very close to the same area in an open container and exposed to the fire ball.
5)my entire work shop area is a fire trap - scraps of paper, wood, foam, glue, paint, flamable liquids, planes and parts of planes, drapes, cardboard boxes, etc etc all withinn the range of sparks and embers from the packs.
6) directly above the fire proof charging box I have planes hanging from the ceiling as well as wooden shelves stacked with all sorts of "stuff". Much of it would burn quite well once ignited.
7)left the room while the charge was going - but I doubt that it would have helped if I was in the room. I had looked at the pack just a few minutes earlier and it looked fine. Actually I think staying in the room is an unrealistic expectation.

Things I did right - more or less.
1) had the pack mostly in/on a fireproof surface - Brinks box - so at least the bench didnt catch on fire.
2)had a fire extinguisher by the exit door and knew exactly where it was and how to use it.

The dry chem ABC extinguisher worked very well in containing the blaze. I think I was somewhat lucky too in that it seemed like the pack cells went off in sequence and not all at once. There seemed to bt at least three seperate "vents" while I was fighting the fire.

I got to the room maybe 15 seconds after hearing the woooosh/crackle/pop/roar (there was no loud bang). I knew instantly what had to have happened when I heard it. It was not all that loud tho. If the door to the work room had been closed and the TV on in the other room, I might easily have missed it.

When I got to the door dense smoke was already pooring from the room. Lots and lots of smoke. The fire ball was at least 2 feet hi and as big in diameter. Very intense roaring rushing sound like a hi powered blow torch. NOT a simple burning. Very intense.

Within a second or two, as the stream from the extinguisher hit it, the flames were driven down and disapeared. There was still whooshing sounds tho, so i think it was still venting, but no flames. I backed out of the room to get some air and open windows, but I heard the fire start back up. Kind of a pop and more intense woshing. I suspect the next set of cells cooking off. The charger was still going at that point - I could see the LED's glowing.

By now the smoke was very very thick but I hit it again with the extinguisher and it went out again. I ran out to get a few breaths and came back and it was burning again. It felt like I did that a dozen times and it took hours, but Im sure it was only a minute or two at most.

I was finally forced to leave the house to get some air and fortunately the fire did not re-start.

I used almost the entire extinguisher.

It was a very close thing.

I am amazed nothing else in the room caught on fire. I have burn holes thru every plane and thru most all of my Depron that was laying around and burn marks on the floor and scorched items on the shelves above.

Some of the lipos in the adjacent container have melted shrink wrap and burn pits on the shrink.

I had around 25 small to medium lipos packs (420 - 4000mahr) all in the imediate area and exposed. I had just finished a marathon balancing/checking routine on almost all my packs. I had been putting them into that one fire box as they got done so I could keep them sorted.

Even tho I lost my TX and a ton of stuff and at least 4 planes - I was increadibly lucky.

Before the next time I do any charging - I will have at least three extinguishers on hand in addition to a completely re-designed/set up charging station. I dont know exactly how yet.

Im not giving up on lipos - but I will be a LOT more carefull.

Be carefull guys.

I was certain it would NEVER happen to me. I know this stuff inside out. Im carefull. I have all the good toys. I have the safty devices. At my club they call me "electric Larry". Im the go-to guy on this stuff. Couldnt possibly happen to me. No way! I tell OTHER people what NOT to do all the time.

(sigh)

Larry
Mar 10, 2006, 03:02 AM
Registered User
ebill3's Avatar
WOW. First, really sorry it happened, but tickled that you have your well being and home intact.

Thank you for the very comprehensive report in your last post - they are words to learn from. Like you, "I'm not giving up on lipos - but I will be a LOT more careful." Even though I charge outside and away from structure, I'm going to have an extinguisher at the ready.

Bill
Mar 10, 2006, 08:42 AM
Registered User
Jurgen Heilig's Avatar
I don't believe it. The man who kept claiming the Graupner LiPo Charger 4 to be "made by the devil" is charging a 5s2p Lipo pack without a dedicated LiPo Charger, without a balancer and doesn't even monitor the first charge?

It just proofs - yet again - that human error is more likely to happen than technical faults. Here is another example:

https://www.rcgroups.com/forums/showthread.php?t=489789

Still, I am glad that nothing more serious happened to Larry.

Jürgen
Mar 10, 2006, 11:32 AM
Fly by grace
rkhoo's Avatar
Larry, most of us charges out lipo such liker you did, in out workshop. What should we do? Balancer is only one item in the possiblw Murphy's list.

I think I am gona charge my Lipo in a non-flamable BOX - - not something that will trap presure and explode -- something bigger, like my shower room -- those stand-up style with 2 side ceremic-tile and 2-side glass door. If anything happen, it will be contained in there -- I guess

The lipo is stored inside a metal cash box with some holes.

I figure if venting happens, nothing in the shower will burn.
Mar 10, 2006, 12:12 PM
Registered User
Larry, as everyone else sorry to hear your problem.

Try to remove the human error by having systems that avoid problems.
Use a charging sytem that has fail safe process
- charger that does individual cells ie Hyperion / TP balancer
- charger that recognises cell number - Apache 2500
- for larger packs - consider avoiding having 4s,5s,6s - too much confusion, stick to 4s, 6s, 8s or 10s. The charger will always be able to be clear if it is correct.


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