DJI Mavic, Air and Mini Drones
Friendly, Helpful & Knowledgeable Community
Join Us Now

Lithium battery fires, what's the right info ??

MAvic_South_Oz

Well-Known Member
Premium Pilot
Joined
May 25, 2017
Messages
8,491
Reactions
7,976
Age
61
Location
South Australia, the great southern land
..
The recent Gator / drone post here . . .


. . . shows vastly different advice / opinions regarding dealing with lipo / lithium fires.

I didn't want to clutter up the thread there, so started this one . . . read the above for a bit of background, down to my post diverting here . . .

Very toxic and Hot once that battery is exposed to water…

This is an oldie but goodie:


..
Hmm, ok big news to me, so I'm glad it has been brought up.
Very interesting video posted by BigAl07.

I really hate seeing this go from the poor alligator to lithium and water, but it's important to find out what is correct here.

Copious amounts of water are what you are supposed to do when the lipos start getting hot, smoking, to cool them before they flame out.
Fire brigades use that 30,000 - 40,000 gallons of water on Tesla battery fires that have flamed out, you'd think they know (?).

It's been discussed many times on the forum, and specific threads have shown airlines themselves follow this procedure.

One thread I actually started after finding the current Airbus lithium battery procedure . . .


Right down near the bottom, flight crew procedures.

I re read a lot of info just now, and some of it says after an airline cabin lithium fire where the crew has extinguished any flame out . . .
  • Once there are no more open flames:
    • If it is not possible to remove the burning/heating device from flight deck, pour water or non-alcoholic liquid on the device to cool it down. Be aware of possible explosion. Tests completed by Airbus have confirmed that a small quantity of water aimed at the device is sufficient to cool it and mitigate the consequences of the thermal runaway.
    • If it is possible to move the device: transfer it to the cabin and use the Cabin Crew Lithium battery procedures to secure it, by immersion in water or non-alcoholic liquid.
I do believe what I've read from this and other sources, the same procedure is used if the battery pack is found getting hot, or is smoking and not yet flamed out.

It'd be good to get some opinions on this, and there is certainly some very conflicting info..

Firstly, are lipo and general lithium batteries the same in this regard ??
I always thought they were, as they treat a laptop, phone, or lipo battery fire the same.

Other links I found referring to use water to cool the battery . . .

CASA (Australian equivalent of FAA)

FAA info (link to following NBAA article)
Lithium Battery Safety Resources


And a really interesting chart that's been posted here before, up to date (end June 2021) FAA listing showing all lithium fire incidents since 2006.

 
  • Like
Reactions: eva2000 and BigAl07
From Bridgehill.com "Traditional fire extinguishers, such as foam and water, don’t work on lithium battery fires. The only way to extinguish a lithium battery fire is to flood the battery with water. A Lithium Fire Blanket will safely isolate a lithium fire battery for hours, until it can be flooded and extinguished."
 
  • Like
Reactions: MAvic_South_Oz
Airlines should build small box like containment systems that can be flooded with water and the smoke vented to the outside of the airplane. Grab a flaming phone or laptop with a Lithium Fire Blanket, toss it in the box, shut the lid, press a button and flood it, all the while the smoke is vented from the cabin. Patent number 265347dge5H.
 
The fire blanket is a great idea to take the battery to a better safe storage area / receptacle.

In the airbus article, they actually recommended a toilet to place / immerse the battery.


"Once the fire has been contained and the device can be safely moved, this procedure recommends to place receptacle where the burning/heating device was immersed in a lavatory and subject it to regular monitoring.
The lavatory is proposed as it contains a means of smoke detection, but is also a location that can secure the device away from the passengers and provides waterproof floor designed to receive water in case of turbulent conditions."

Suppose layer with plastic rubbish bag to keep water in there, most toilet bowls are dry from memory (yeah, that long since covid and flying lol).

The idea of a vented box that can later be filled with water (if it is indeed the right way to go) is a very good one, something for the aircraft design stage, so not sure if anyone's given that any thought before.
The fluoride outgassing sounds as much a threat as the fire.

Everything I read does say immerse / cool with water, so surely it must be right.
The video on the other post might be the difference with raw lithium, no casing / housing.
 
  • Like
Reactions: BigAl07
Note that all the cited articles state that water immersion is to be used AFTER the flames have burned out. Using water earlier is a whole different story.
 
I know when I raced RC cars that we always had a few buckets of sand around to dump on the battery to smother the fire. Once the fire was out they would be put in a bucket of water to prevent it from reigniting.
 
This video is interesting.


He takes opened AA batteries and puts the strips of lithium into water, it ignites violently, but burns out fast.
At 7:10 he puts a partially open lithium battery into the same bowl, and it does nothing.

Maybe in a cover, or almost complete cover, the batteries can be immersed relatively safely ?

Note that all the cited articles state that water immersion is to be used AFTER the flames have burned out. Using water earlier is a whole different story.

I did note that, but when they are in early stages of starting to go up, starting to smoke, there are also docs that recommend cooling with clear, non alcoholic fluid.
Most times these fires might be well past this stage, and a suitable extinguisher is best used.

This actual Lithium battery incident on a flight linked to below is really interesting . . . need to click read report, and down the bottom the FAA guide on dealing with thermal runaway.

Investigation: AO-2016-066 - Personal electronic device fire in-flight involving Boeing 747, VH-OJS, 500 km WNW of John F. Kennedy International Airport, United States, on 21 June 2016

They say cooling with water prevents overheating of nearby damaged cells, and thus a greater fire.

Many bits and pieces I read on this said a water / pure lithium fire burns very fast, mitigating the duration of flare out, while a normal burn takes a lot longer, builds thermal runaway, damages and spreads to next cell(s) in the pack, etc.

I feel now that there is no perfect way to deal with a lipo fire at any stage, a chemicals powder type extinguisher is probably best first up, especially if flames are present.
Then cool with copious amounts (immerse) in water to cool the pack.
Some sites said it's best to then place the pack into a bucket of highly salt water to kill it totally.

I've certainly learned something about the lithium reaction in water, and the outgassing being quite noxious, fluoride and no doubt the plastics melting would be a bad combo.
 
everyone should have a lipo bag to charge and store their batteries in

If you aren't nearby to catch a fire develop, to extinguish / cool a battery or batteries, then lipo bags would be a great addition.
More or less having them wrapped in a fire blanket already.

Also for travel by any means, I'd rather have a battery in a bag, than not.
Car, plane overhead locker etc, in the event one decided to go up.

I'd say though, much safer / better to have a bag for each battery, reducing the chance of thermal runaway if one goes bad and ignites.
In a single bag they would likely spread from battery to battery and create a bigger problem.

I've got lipo bags, but use them at work for storing cash in a safe (the safe is fire rated for an hour, but can go to 180c in that time).
They are metal zippered and have a lid flap over the zipper too.

Lipo bags come in all sorts of shapes and sizes, so using them individually for batteries is easy and not too space hungry.
 
  • Like
Reactions: eva2000
From what I have read, and I am no expert on this, lithium-ion batteries contain little or no lithium metal which is what reacts with water. I have a Mavic Mini which uses Li-ion batteries. Are other types used in different models?
 
  • Like
Reactions: MAvic_South_Oz
DIY Solar energy guys drop packs that catch on fire and are like 1-2KW in size into tub of water. Completely submerged is the key shot from what I can see.
 
  • Like
Reactions: MAvic_South_Oz
From what I have read, and I am no expert on this, lithium-ion batteries contain little or no lithium metal which is what reacts with water. I have a Mavic Mini which uses Li-ion batteries. Are other types used in different models?
DIY Solar energy guys drop packs that catch on fire and are like 1-2KW in size into tub of water. Completely submerged is the key shot from what I can see.

From the videos above, there is a thin sheet of lithium rolled / folded up into what makes up the battery shape.
Obviously our type is contained in the casing, which may prevent it from reacting with water.
Videos show full exposure of lithium sheet to water, no exposure (in the cell casing), and the partial case damaged.
Only the exposed lithium sheet reacted violently.

Could be an oxygen thing ?
Obviously that's why if flaming out you use a chemical type extinguisher.
Maybe before flaming out, in that violently smoking stage, immersion in water not only cools the battery, but deprives it of oxygen ?
Same for after an extinguisher has been used on a flaming out battery.

I'm sure I've seen videos of our encased batteries being tested in the past on YouTube.
Will revisit tonight and take a look if I can find anything really specific as to fire and controlling it.
 
..
If any drone pilot (especially with online drone content / reviews / tutorials) has a battery that's beyond flight service, or swelling etc wants to do a drone battery fire test and extinguish, let's just say that would likely be a first on YouTube.

The closest I can find is still the video of the plain energiser lithium cell test (post #7) at 7:00 mark he places a partially opened battery into water, and after ~ 1-3/4 minutes it's still as it was when dunked.

This sort of supports the closed shell theory that lithium can be placed in water when encased, or mostly encased.

I found another video with a REALLY swollen M1P battery here . . . he never tried to put it out, just spiked it and it only smoked heavily, no flame out.
Pile of molten plastic and remains.


For a good test, 5 batteries would allow for even better comparisons.

Put a complete one into water, and leave it there to see if anything happens.
Partially open / crack a case, place straight into bucket of water to see if anything happens.
Spike one, let it do it's own thing until burned out.
Partially open / crack a case, spike, fight with chemical extinguisher, then place into bucket of water once flames are gone.
Partially open / crack a case, spike, place straight into bucket of water once flames are gone.
 
  • Wow
Reactions: eva2000
From the videos above, there is a thin sheet of lithium rolled / folded up into what makes up the battery shape.
Obviously our type is contained in the casing, which may prevent it from reacting with water.
Videos show full exposure of lithium sheet to water, no exposure (in the cell casing), and the partial case damaged.
Only the exposed lithium sheet reacted violently.
Lithium -Ion batteries do not have the sheet of lithium/metal that reacts with water. Those are common AA ( non rechargeable) Energizer Ultimate Lithium type batteries.
 
Lithium -Ion batteries do not have the sheet of lithium/metal that reacts with water. Those are common AA ( non rechargeable) Energizer Ultimate Lithium type batteries.

So how about your experience with this in a more expanded reply ?
The chemical or make up differences that is.

I can find the differences between Li-ion and Li-po no probs, both similar in way they are made, but one with liquid (Li-ion) between the +/- electrodes, and Lipo with a dry solid or gel instead of liquid.


What I'm not sure about is how they relate (if at all) to the cells in the video Energiser Ultimate Lithium

They obviously ALL contain lithium, react violently to cell penetration (damage) and / or water.
 
Actually, lithium-ion batteries contain very little lithium. As I mentioned prior, I am no expert on lithium batteries, but the construction information is easy to find online.
 
..
I don't think the amount of lithium in any of these types of battery matters, if they go up, they go up.

After some reading, I'm reading Li-ion and Li-po batteries contain about the same quantities of lithium.
They are basically the same, one battery website made a comment Li-po batteries should actually be called 'lithium-ion polymer' batteries, as the make up is almost identical bar the liquid vs gel / solid isolation between electrodes.

One source quotes amount of lithium in all these batteries as approx 8g per 100 Wh.
So a M1P battery (43.6 Wh) would have about 3.5g of lithium, not much at all, but then does that matter ?
If they are volatile with that small a amount in them, they will all do the same, Li-ion or Li-po.
 
Lithium-ion batteries do not contain lithium in a pure volatile form, like the energizers in the video, and shouldn’t react with water in the same way.
 
  • Like
Reactions: MAvic_South_Oz
Put out with a class B extinguisher, in case that doesn’t export that is a flammable liquid extinguisher. Treat it like a gasoline (petrol for export). Appearantly as others have mentioned lipos don’t contain raw lithium which is a flammable metal and require a class D extinguisher, same as sodium and magnesium.
Neither flammable metals nor flammable liquids play well with water unless in overwhelming amounts.
 
Lycus Tech Mavic Air 3 Case

DJI Drone Deals

New Threads

Forum statistics

Threads
131,006
Messages
1,558,796
Members
159,987
Latest member
fbri7