When batteries go boom - Emergency equipment and protocols

[Village_Idiot]

Came across a number of articles and other forums posting about a possible LiFePO4 battery related explosion (in Germany).
The click baity part…

(pic source)

more images

In short, allegedly a 30KWh battery consisting of 3 (2 older and one more recently purchased 200Ah LiFePO4 batteries) might have played a role in an explosive event that lead to the partial collapse of a residential building. While it is somewhat interesting to speculate on what happened and even IF the batteries played any role, something else entirely caught my attention in the home owner being quoted as saying:

“I was in the living room at 1:57 p.m., lying on the sofa to relax,” … “The smoke alarm sounded, I saw smoke coming out of the basement and alerted my colleagues from the fire department,” … He then sent a WhatsApp message to his wife, who was at work late that day. When he wanted to leave the house from the kitchen and wait for the fire brigade, the explosion occurred, making the house uninhabitable

(*emphasis my own)

Made me wonder, after fusing and all other proper electrical standards-based parts of a residential install are ticked off - what attention is actually paid to the potential part when things do go wrong?

Don’t think I have seen many South African homes with smoke detectors/alarms. How many people have fire extinguishers in their homes? What is the plan when you or someone else in the home walks past and notice a weird smell coming from the battery bank?

[TheTerribleTriplet]

@Village_Idiot

How many people have fire extinguishers in their homes?

With Lifepo4 fire, normal electrical fire extinguishers won’t work.

FWIW, Lifepo4 batteries exploding … is there any other evidence of such?
Cause as far as I’m aware, in general, lithium iron phosphate batteries do not explode or ignite.

Smoke alarm, then the explosion, wonder what the chances are there was a gas leak maybe too … ?

EDIT: Protocol in my house if there is a problem with the batts … RUN!!! outside and stay there.
I pondered on getting a gasmask and having the cable snippers close by so that one can get in, snip the battery cables, and push the bank outside, seeing it is on wheels.

Then dump the bank in a pool, in lieu of one, a water tank.

WIP.

[plonkster]

@TheTerribleTriplet

With Lifepo4 fire, normal electrical fire extinguishers won’t work.

I believe an ordinary powder extinguisher does help with a LiFePO4 fire, because it cuts off the oxygen, and unlike it’s NMC cousin, it doesn’t make its own oxygen in the process. It doesn’t cool it down, however, but water does work very effectively.

I have a fire extinguisher in the same room as my batteries.

I too very much doubt the story that the battery caused the explosion. But it will depend what battery was installed. The first comment below the PV-magazine article asks that same question:

Erstmal fraglich, ob es überhaupt wirklich ein wirklicher LFP in Gänze war. LFP gelten als sehr sicher.
Hier wurde von einem kleinen, unbekannten China-Hersteller Akkus über Alibaba.com bezogen.
Dann wurde es selbst zusammen gebastelt.

[plonkster]

Wow, the newspaper article says this:

Einzelne Teile des Hauses wurden durch die Explosion bis auf die Straße geschläudert

Some parts of the house were thrown onto the street by the explosion.

[Village_Idiot]

@TheTerribleTriplet

Lifepo4 batteries exploding … is there any other evidence of such?

@plonkster

I too very much doubt the story that the battery caused the explosion. But it will depend what battery was installed.

There is really not enough facts known, and likely may never be known in this case, to conclusively prove the batteries were involved. The home owner however is an electrician and volunteer firefighter and seems to consider the batteries as being involved (no idea as to his competency).

So, to speculate, with apologies to the chemical engineers out there… I think it is possible under very specific circumstances (which could have been present here) to have an explosion related to the batteries, but technically not the batteries/cells that explode.

When LiFePO4 starts venting during thermal runaway a large percentage of the vented gas apparently consists of hydrogen (up to 50%) and methane. While NMC is considered the more “burny”, these guys concluded:

The primary types of BVG consist of hydrogen, carbon monoxide, carbon dioxide and hydrocarbon gases for both LFP and NCM batteries. However, due to the significant amount of hydrogen and hydrocarbon gases with low LEL values, the LEL values of BVG for LFP batteries are lower than NCM batteries, demonstrating the higher deflagration risks for the former.

BVG= battery venting gas
LEL=Lower Explosive Limit
Deflagration=Explosion with flame speed lower than the speed of sound.
i.e. LiFePO4 may produce more potentially explosive gasses than NMC.

When you put this in an enclosed space you likely increase the chances of reaching a concentration where only an ignition source is required for an explosion.

In the German case, an old property listing indicates a basement of about 80m² but having 2 smaller rooms (pic of the inverter room suggests possibly one of these smaller spaces - compare distance from the multiplusses to the opposite wall with the wndow blown out). There is also mention of an Oil heating system and possibly a boiler (not known if actually present in the same room as the batteries but obviously both potential sources for an explosion themself or at least an ignition source - assuming auto ignition temp was not reached IF a cell started venting during thermal runaway). So, fairly large cells, at least one starts thermal runaway and a cascading release in other cells lead to a build-up of H₂ and/or CH,₄, in a smaller enclosed space, meets an ignition source… I am sure someone will pop around with the calcs to show you would need cells larger than the contained space to reach the required concentration/ratio to make an explosion feasible - but in theory for me it seems not in the realm of impossibility.

@TheTerribleTriplet

EDIT: Protocol in my house if there is a problem with the batts … RUN!!! outside and stay there.

@plonkster

I have a fire extinguisher in the same room as my batteries.

Vacating the premises seems a sensible approach. Think I will start looking into smoke alarms (things happening while sleeping coming to mind…).

[Sarel.Wagner]

Got one of those nano particle jobbies at my other door about 3 meters away and a big azz industrial CO2 just outside the door. Smoke alarm above the batteries, another one just outside that door about 2 meters away, also on the wifi system.

GefusedAlarmGroetnis

[Richard_Mackay]

@Village_Idiot

Don’t think I have seen many South African homes with smoke detectors/alarms. How many people have fire extinguishers in their homes?

Indeed! In my neighbourhood we have had 2 house fires this year. One doesn’t find out what the cause of the fire is so you can learn from their misfortune. (You can’t ask since you will probably get the ‘official’ response)

[plonkster]

@Village_Idiot

large percentage of the vented gas apparently consists of hydrogen

I also noted that from the one German article, which is interesting news to me. Didn’t know that.

[TheTerribleTriplet]

@plonkster

I believe an ordinary powder extinguisher does help with a LiFePO4 fire

Fire Extinguishers which are ineffective on lithium-ion battery fires |...

Powder
Powder has no cooling effect on Lithium-Ion battery fires, which burn at temperatures up to 1000°C. The powder crust will only form on horizontal surfaces, not vertical, therefore no oxygen barrier is formed. The propagation of the fire due to continuing thermal runaway is unavoidable.

Foam & Wet Chemical
The usual film formed by foam, on a fuel fire for example, is not able to cling to vertical surfaces around the battery compartment therefore providing no oxygen barrier. In addition, any film that forms on the horizontal surfaces of the battery in thermal runaway will be damaged by the residual heat. Likewise, the soapy film formed by Wet Chemical, when used to extinguish burning cooking oil, will suffer the same limitations as foam.

CO2
CO2 has a good cooling effect on the fire and will provide oxygen starvation while the CO2 is directed onto the fire, but as soon as the CO2 is removed, the continuation of thermal runaway will reignite the fire.

Water - hence my idea of a water tank/pool.
Water will provide a cooling effect and extinguish the flames from the Class A fire resulting from the burning surroundings of the Lithium Ion battery in thermal runaway. However, the water that is not evaporated by the heat of the fire will run away from the fire and not provide any oxygen barrier and won’t prevent thermal runaway. Re-ignition is inevitable because thermal runaway will continue.

This is what is needed:

The Effective Solution
The Lith-Ex extinguishers are ideally suited for Lithium-ion based battery fires. The Lith-Ex Extinguisher is compact, lightweight, easy to store, non-toxic and environmentally friendly. It will extinguish uncontrollable flames, quickly cool the excessive heat and prevent re-ignition, something that an ABC powder extinguisher or other liquid-based extinguishers will not be able to do on a Lithium-ion battery fire.

Lith-Ex 9 Litre Fire Extinguisher - Firebreak SA

[Village_Idiot]

@Sarel.Wagner

Smoke alarm above the batteries, another one just outside that door about 2 meters away, also on the wifi system.

smoke alarm sends a message using wifi network when triggered?

@TheTerribleTriplet

The Lith-Ex extinguishers

not cheap hey… seeing SA prices of about R1000 for 500ml to R13 000 for 9L

[plonkster]

Aaa yes, I also googled this before posting, but I noticed that the first link was not talking about LiFePO4, but more in general, and therefore wasn’t really relevant.

It is also why I said “I believe it does help”, and why I mentioned that you need to cool it down.

The powder extinguisher I keep is mostly for electrical fires. Which is also a thing.

[TheTerribleTriplet]

So now I’m thinking … getting an extinguisher at ±R13k … but I don’t KNOW if it will solve the problem, or do I need one 500ml or 2 x 9kg … one will know for a fact when one has had the experience.

So I sit and think … if the battery cabinet is waterproof, sides and bottom, high enough to cover the tops of the cells, IF it ignites, then fill it battery cabinet with water.

Like those firefighters with that Tesla.
Dig 1 hole in the ground. Then fill hole with water. Push one Tesla into the hole. Problem solved.

What do you guys think?

[Sarel.Wagner]

Yes they do, also the usual waking ya from the dead screams from the unit itself. Also have the WiFi units display in my Home Assistant dashboard.

Groetnis

[Village_Idiot]

@TheTerribleTriplet

getting an extinguisher at ±R13k

Claimed locally developed product aimed at lithium fires that seems fair bit cheaper

Introducing FlameBlock Lithium Black: Locally developed fire extinguisher for...

see some prices around R3000 for 6L

@TheTerribleTriplet

but I don’t KNOW if it will solve the problem

@TheTerribleTriplet

if the battery cabinet

actually a very interesting question… will any fire extinguisher help much if the batteries are in an enclosure ? The video/testing footage I come across all have just a bunch of uncovered cells where the extinguisher then “easily” can cover flames, cells, etc.

I suspect having some fire fighting equipment is a good idea - having as much warning as possible probably more important.

[TheTerribleTriplet]

Introducing FlameBlock Lithium Black: Locally developed fire extinguisher for...

6L one
https://www.takealot.com/flameblock-lithium-battery-fire-extinguisher-6-litre/PLID94090439

[Richard_Mackay]

I disconnect my modest PV panels when I’m on holiday and the house is empty.
Does anyone disconnect their batteries??

[mmaritz]

@TheTerribleTriplet

What do you guys think?

I’m thinking I did the right thing and paid extra for extending my main in and out cables to the garage which is free standing… “small” 1m passage between it and main house… All my PV bits are now in garage so a buffer between that and main house. PV on house roof but fused on roof as well.

[TheTerribleTriplet]

Have seen photos of garages caught alight due to lithium batteries in them so when contemplating the garage I thought of the vehicles in there, the fuel inside them, the paints, and other chemicals we tend to store there.

You have a chemical fire, a fuel fire, and a lithium fire, so one needs more types of fire extinguishers, not so? … or just walk away and watch the spectacle. Or if it is REALLY bad and it spreads. What is the worst that can happen? Where does one draw the line?

So no matter where said battery is, where the line is, how does one extinguish said lithium battery when it gets a “hissy fit”, fast and efficiently?

Fire extinguishers are absolutely a must, but me, what if you don’t have enough extinguishers on hand? Or the right one? How can you stop the thermal runaway one time “dead”?

Hence the “watery grave” idea … irrespective of where said bank is placed.

EDIT: Put differently.
WHEN that lithium bank has a thermal runaway, “jy is in die k_k”. How do you stop it dead?

The fire alarm goes off on the battery, so you grab a gas mask and start to submerge it in water, one idea, ja?

Cause when the fire department eventually arrives, they are going to pour thousands of liters of water, and whatever else they have, on the resultant fire/s … after which the bills will start coming in to put one back where one started.

Another idea:
Put a couple of Victron Temp sensors on/between the cells connected to a Cerbo.
If they exceed X temp, send a warning.

[Village_Idiot]

This overlaps a bit with some of the content from the 18 cell 48V bank thread but I will put it here.

The practical feasibility of pushing around a “smoking” Lithium Battery (even LiFePO4) to get to an extinguishing source seems questionable. As does trying to contain a “fire” without proper PPE and equipment.

The following is focussed on educating firefighters, is at times somewhat alarmist, mostly deals with examples of EV fires (but from what I gather once thermal runaway has started the chemistry of the cells do not really change the risks).

Seeing the rapid development of the vapour layers (which might be confused with smoke) for instance makes me question things like how “navigation” will work with limited visibility. The toxic nature of what is vented (possibly worse with LiFePO4?) is another hazard. The very real danger of a very hot jet of gas being released with a face close to the surface seems another very unpleasant risk.

In short, unless another human life is at stake - vacate (GTFO) and let insurance deal with it ?

Another one that deals with a possible understanding of how even LiFePO4 can have results like that which are found in the first post of this thread.

[TheTerribleTriplet]

@Village_Idiot

… pactical feasibility of pushing around …

Yes, that is a rather biggish “point of order”.

@Village_Idiot

(GTFO) and let insurance deal with it

That is THE biggest “point of order”.

Still like the idea, even though it is not that good an idea, of submerging the bank very VERY quickly in deepish fluid … seeing as water can be a cause for big concern, bar, dumping it in the pool.