LIPO on fire: what can we do to control it & limit damage?

[JIM MARCUM]

We now know why there was a LIPO fire incident at the FE Nationals at Legg Lake. Trying to save & charge a 6S LIPO with one low voltage cell, unbalanced, and leaving it unattended. Unless you have participated in a large FE racing event, you can't imagine how intense the pressure is on a competitor racing boats in five different classes. We all make mistakes, but we should learn from them.

With that knowledge, hopefuly we can avoid having that happen to us, and how to limit damage if it does. Learn the basic rules of how to handle, charge, discharge LIPOs - and follow them. Read the paperwork and warnings included with your LIPO. And know what to do if your LIPO catches on fire.

That said, this has opened an interesting can of worms. The most experienced and knowledgable FE racers on the planet disagree on what is the best way to handle a burning LIPO, and how best to control/limit damage caused by the fire itself - as well as how best to limit personal physical damage caused by inhaling that toxic white smoke. We all seen to agree that once a LIPO battery is on fire, it is virtually impossable to stop the chemical reaction. However, it is possible to control it and prevent spreading the fire to other combustables.

Suggestions include:
1. Toss the burning LIPO in a bucket of water
2. Don't throw the burning LIPO in water - (electrocution?)
3. Throw the Burning LIPO into saltwater
4. Throw the burning LIPO in a metal bucket & cover it with sand

With the exception of #2 (it won't happen), all suggestions will control the LIPO fire, and limit setting other combustables on fire. If it ignites while charging it - disconnect the battery from the charger - DO NOT put water on the charger itself or you risk electrocution - a very bad thing. None address the toxic smoke issue.

So exactly should you do if your LIPO catches fire?

Here's my thoughts:
1. Get that burning LIPO out of your house/trailer and get it outside immediately
2. Keep the LIPO fire away from any thing combustable
3. To limit exposure to the Toxic smoke - try to stay upwind - and do not inhale it
4. Use fireproof bags to charge & store your LIPOs

This is a critical SAFETY matter - we must have valid procedures in place to limit unecessary harm to people, pets & property - we must get this information out to all FE boaters quickly, and such information must be readily available to all of us in the future. Especially newbies.

What are your thoughts?
Is it even possible to put this form of chemical fire out?
How dangerous is it really to inhale that smoke?
Will you encounter medical issues later?

JIM

PS: Keep this thread on the Q&A forum for maximum viewing exposure. If it's burried in the Batt/charger thread, a lot of people won't see it. THX, JIM

[HTVboats]

With all the activity on the incident at the nationals I am surprsed there isn't more info comming out here. What I did get out of everything as Ken also stated we get too comfortable and need reminders, which did happen. No one was injured which is positive as property is easily replaced, but bodies take time and sometimes damage can be permanent. In my years as an insurance agent I heard many accident reports from my clients and the first question I had was anyone hurt? If the answer was no then it was a good day as accidents will happen now and in the future.
It seems that improperly charging cells and especially stressed cells is not good. Makes me wonder about how long cells should cool before recharging? That and I have puffed batteries that still perform well, but are not like they came out of the box. How much more liable are they to fail and become incindiary. Manufacturers package batteries well to store and ship with foam and bubble wrap which makes me think impact is a large consideration. I have many bags with 3-5 batteries in large lipo bags and then stored in metal boxes in a old metal file cabinate. if one battery can ignite others touching them I have to rethink storage. An individual cell on a charging stand though dangerous would be easier to contain than muttiple batteries igniting others? Not sure what is better here but I am surely not opposed to spending $100-200 dollars for the proper extinguisher. What is the proper extinguisher? Any firemen out there that have factual training on the subject?
I hope we will get more feedback here and thanks for posting it Jim as you have taken some (excuse the pun) flames elsewhere, yet I feel you are sincere about getting proper info to everyone.
Mic

[NativePaul]

I was a safety officer of my club when LiPos were finally ratified for boats, and on the advice of my local fire brigade I bought a CO2 extinguisher for the club, as they produce the fuel provides its own oxygen smothering it in foam or powder or drencing it in water wont work, and the only chance of extinguishing it is to lower its temperature back down below the runaway reaction temperature, which may or may not be possible within the short run time of a Co2 extinguisher (they had not tried it or even seen a LiPo fire in real life). Thankfully we have still not had use of it so I have no idea if it will work or not, but it is at least safe to use on any secondary fires we are likely to have and will not cause any further damage.

I believe that even if possible, extinguishing a LiPo fire is likely to be difficult/time consuming and containment is a good idea, at home I charge with a window open rather than an extinguisher at the ready, and at the lakeside it would go straight in the lake where it may continue burning but the risk of secondary fires would be minimised.

To further the query as to the benefits of charging in LiPo bags, I was at first dead against the ruling that LiPos must be charged in bags or other fireproof container, as I am a firm believer in prevention over cure, and at home or boating on my own I much prefer to be able to see and feel the LiPo on charge so I can disconnect it at the first sign of any puffing or temperature rise before a fire happens, whereas if its in a bag you would have no idea until it happened. However I was failing to think about how much is going on at races, for me at least it is impossible to monitor the pack nearly as much as I would like to because I'm always off running another boat or doing a duty, helping a mate, scrounging something, or just chatting at someone else's pit table, may only get to check it every 10 mins or so, and I do now think that it was a very good rule to have put in.

Any smoke inhalation is very dangerous even if it is just non-toxic carbon soot, it stops the lungs working properly and leads to asphixiation, the vast magority of house fire deaths are from smoke inhalation rather than burning.

I have no-idea if there are long term issues that don't present themselves in the short term, and I doubt anyone does, as they just havent been around long enough to find out.

You said in the other thread that several fire extinguishers were used and did nothing, you also mentioned a mess so I am guessing that at least one of them was a powder type extinguisher, do you know if any of them were CO2?

[oscarel]

I didn't see anything on Hyperion or Thunder Power's sites, but did find these two links.

http://www.4-max.co.uk/pdf/dos-and-donts-lipo.pdf

Only charge in an isolated area away from other flammable materials and on a non conductive and non
flammable surface. Use a LiPo Guard bag or use a non-conductive container like a casserole dish with a lid
as it will help contain any fire. LiPo battery fires can not be extinguished with water. If a fire occurs, either
cover it with sand or better still salt. On no account use water to extinguish a fire. Water acts like petrol on
a LiPo battery fire.

http://www.maxamps.com/lipo-care.php

Keep a dry fire extinguisher nearby or a large bucket of dry sand, which is a cheap and effective extinguisher.

[Doug Smock]

Some interesting stuff here. http://www.electrochemsolutions.com/...ling_Guide.pdf

[Doug Smock]

http://www.safetyemporium.com/ILPI_Site/WebPagesUS/detail.htm?09592

http://www.conney.com/Product_-Amere...70_11367_11367

Water is looking better and better along with the 5 gal bucket of sand and ABC Extinguisher that I take to racing events.

D.

[Steven Vaccaro]

my question is, thatin everything everyone is reading online, when are the fires happening? to me it seems while charging. if thats the case we should all be charging outdoors. comments?

[Doug Smock]

http://www.safetyemporium.com/ILPI_S...tail.htm?09592

http://www.conney.com/Product_-Amere...70_11367_11367

Water is looking better and better along with the 5 gal bucket of sand and ABC Extinguisher that I take to racing events.

D.

I think I'll round up one of these as well.
http://www.cpr-savers.com/emergency/fireblanket.html Maybe have it cut up into 4s and have the edges sewn.

[LuckyDuc]

While charging mishaps do happen, the lipo fires that I have personally witnessed (at the airfield) were all caused by damaged cells... Damaged in a crash, damaged by over drawing the packs, or faulty connections/dead shorts.
Understanding how to identify a damaged pack may help people mitigate risks. Any suspect pack should be immediately removed from service and placed in a fire containment vessel.

[BHChieftain]

Hi,
I charge my lipos in the fireplace-- if there's a fire, the smoke goes up the chimney.

I store my lipos in my wood burning stove (I know a member here who has reported a stored lipo self combusting... rare, but it can happen).

Chief

[oscarel]

So much conflicting info. I did come across this from the FAA.

http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2020-42D.pdf

(4) Class O. Fires involving combustible metals, such as magnesium, titanium,
zirconium, sodium, lithium, and potassium.
b. lithium Battery Fires. Do not treat a fire involving a small number of lithium
batteries as a Class 0 fire. We consider a small number of rechargeable lithium batteries as what
would be found in portable electronic devices (PED) e.g. laptop compulers, cell phones. pagers,
audio/video/data recording or playback devices, messaging devices, personal digital assistants
(PDAs), and two-way radios. See chapter 4 paragraph I f of this AC on fire fighting training for
further information.

f. Specialized Dry Powder. Class D fires are best controlled by dry powder, Follow
the recommendations of the extinguisher manufacturer because of the possible chemical reaction
between the burning metal and the extinguishing agent.
Note 1: Specialized dry powder is not recommended for hand
extinguishers for internal aircraft use.
Note 2: Fires involving a small number of Lithium primary
batteries (containing molten Lithium) should not be treated as class
o fires and specialized dry powder should not be used. See
chapter 4, paragraph If of this AC for a discussion of appropriate
extinguishing agents for Lithium battery fires.

[detox]

I think I'll round up one of these as well.
http://www.cpr-savers.com/emergency/fireblanket.html Maybe have it cut up into 4s and have the edges sewn.

Be sure to use fireproof thread so when your lipos do the nasty.

Could you imagine coming home from work one day to find out that your lipos had ignited inside your home. I bet your house would smell lots different. We have four indoor/outdoor animals, i hope they will be OK.

[Fluid]

The worst LiPo fire I have personally seen occuerd last year at a district race. The racer was bringing his 10S mono in after a heat when it stopped a few feet from the bank and began smoking. We retrieved the boat, tore off the hatch and saw that three of the four new 5S liPos were on fire. We pushed the boat underwater, flooding the boat and immersing the packs. In a few minutes the packs stopped burning and the boat was pulled out. The packs were all toast but everything else in the boat was salvageable.

Why did this occur? Using cheap low-C packs in a high-amp application (150 amp estimated). In theory the 25C/5000 mAh packs should have been adequate for up to 250 amp draws, but clearly the packs were not up to what they were labeled to handle. This exact setup now runs fine on high-C packs.

Lesson - cheap packs are not suitable for high-amp draw applications.....unless you want to risk a fire that is.

DSC00028.jpg



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[D. Newland]

I continue to go through the event at the Nat's in my mind, and I truly feel it's a success story. No injuries, and all things considered, minimal damage. There is nothing that is going to save a LiPo that is in a thermal runaway situation...I think we all know that. It's what we do about the collateral damage.

In hindsight, the one item that was missing was something as simple as a steel dust pan and a galvanized bucket. I'm the one who scooped the LiPos off the counter and I don't know exactly what I was handed to do the job, but it did work. I know the cells ended in a cooler. Hindsight-we should have had the metal items I just mentioned.

I find it important to charge out in the open, and to have your charging station set up to where there is good separation between packs. Eliminate the chain reaction exposure by not having them all bunched together. Use balancers. Though I check individual cell voltage religiously, I am guilty of not using the balance taps all that often. I guess it's questionable if they will save a LiPo that's beginning a thermal runaway situation, but at least it will shut down the charger from pumping more power into the packs and give off an audible alarm.

Have a plan. For you. Though sanctioned events will have a plan, don't rely on it. If one of your packs goes up...what are you going to do? It doesn't matter if you're at a National event or fun-running.

If you're running high-volt boats, you have to more diligent. With Jay's post above, I now know of 4 fires off of the top of my head. 3...and maybe all 4 were 10S boats...and there aren't that many of them running out there. I'd hate to see the high-volt classes get removed from the rulebook for safety/risk reasons.

Don't panic. Be aware that the LiPo is going to do it's thing, and you're just going to have to wait it out for a few seconds and manage the immediate surrounding area for any collateral damage. The thermal runaway situation will calm down. Just like a sparkler or other type of firework. You can't stop it until they run their course.

LiPo's will glow red for 45 minutes if untouched. Remember that, especially when you're done with the immediate threat.

At home, store them safely. Have them discharged to manufacturers recommendations. I keep mine 30% to 50% storage charged and on a metal surface that I give a visual inspection 3-4 times a day.

And, just so some of you know, this is the type of thread I was looking for. It's constructive and helpful and I hope that if we get enough solid information on here, it will become a proof source for the site. I know Terry has extensive resources at his disposal and I hope he comes up with some good information to share. Other racers do, too. For lack of a better word, the other thread was too toxic for good information to be shared.

If we want FE to be the power source of this decade, one thing that is imperative is that we have a tremendous amount of respect for our power source, and help others gain that respect. The amount of attention that is on battery technology will continue to grow...as will the hazards.

[JIM MARCUM]

You said in the other thread that several fire extinguishers were used and did nothing, you also mentioned a mess so I am guessing that at least one of them was a powder type extinguisher, do you know if any of them were CO2?

All fire extinguishers were dry chemical (baking soda) types to the best of my knowledge. I don't think we had any CO2 units available. JIM