Electric car fires: here's how to intervene

Now retired, Lieutenant-Colonel Michel Gentilleau was in charge of training firefighters and people affected by accidents and fires involving alternative energy vehicles. Should you immerse a burning electric car in a pool of water? This is one of the questions he answered for us.

From a dynasty of firefighters

Becoming a firefighter is a vocation. The trajectory of Lieutenant-Colonel Gentilleau (ER) is an example experienced at the family level: “ I have been in the fire service for 40 years. You could even say that I come from a dynasty of firefighters that spans four generations including my grandfather, my father and my son ».

Its major role in interventions on electrified cars is not very recent: “ It’s a twenty-year-long story. I was in Vienne after passing through Paris and Oise. Sdis 86 wanted to build a training center. A congress on advanced mobility was held in parallel with Futuroscope. We were at the beginning of the marketing of the Prius. I met the head of Toyota Europe who wanted to respond to official requests to intervene on hybrid cars on fire ».

The Vienne training center then had a key role: “ We established an intervention protocol on the Toyota Prius only. Then other manufacturers came to see us: Renault Trucks, Renault, Bolloré, etc. The field widened with Colonel Delaunay of Sdis 44 who took care of vehicles running on LPG and CNG ».

A sought-after expertise

Training to intervene already requires knowing the behavior of alternative energy vehicles in the event of a fire or accident: “ We did a lot of testing and burning, particularly with Renault. We have done it on tons of batteries, but also on hydrogen buses. The result was a 130-page document that we relied on for 20 years for our training. ».

The resulting expertise is not only redistributed in France: “ Every two years, we welcome over three days 500 firefighters from 20 to 25 countries and companies like TotalEnergies which are interested in mobility and insurers. The program is rich in dozens of workshops, conferences and round tables. This year 2025, these technical days will be held from May 13 to 15 ».

Demonstrations are also planned: “ There will be burns on electric vehicles and a hydrogen bus. Part of the program is focused on heavyweights. We will also have trials with rDME, a renewable fuel which would be in the development phase. ».

Also readTestimony: this is why Adrien's damaged MG4 has been immobilized for 9 months

Firefighter representative at Euro NCAP

At 64, Michel Gentilleau is not inactive: “ Beyond my former role, I represent the voice of firefighters for Euro NCAP crash tests. I have been sitting in Brussels for eight years now to integrate their demands. Since last year, heavy goods vehicles have also been affected ».

Two types of situations are studied: “ There are of course fires for one reason or another. But also traffic accidents with electrical risks and a possible spontaneous fire outbreak as a result. Thus in Deux-Sèvres last October where four people died in the fire which followed their Tesla leaving the road. My feeling is that this brand's electric cars are the most sensitive to thermal runaway after an impact. We would need to have official statistics to be sure. ».

Our interviewee's team hopes to significantly reduce such drama: “ This is one of the main problems in the world of firefighters. Today, Euro NCAP requires five minutes of stability before the flames so that occupants can exit the vehicle if a warning light comes on while driving. This is too little and does not allow help to arrive. This delta must be much higher, around the hour, so that the firefighters can intervene ».

Immersion or thermal blanket?

It has often been said that it is necessary to immerse an electric car engulfed in flames: “ This is a good answer for isolated batteries, scooters, electric bikes or storage units. However, this is not what I recommend for a car, that would be heresy. Can you imagine the implementation time it takes when a thermal runaway lasts no more than an hour? ».

There is also the solution of thermal blankets: “ I tried some in mid-2024. Some can withstand up to 1,300°C over a relatively short period of time. These covers help limit the spread of heat and smoke. This solution is not easy to implement either. It is rather interesting for confined environments, factories or large companies. It helps avoid the domino effect, i.e. propagation to nearby vehicles. ».

Perforating hydraulic lance

Less known to the general public, the piercing lances: “ Water is an excellent extinguishing agent. It is effective if we can reach the heart of the battery. Which is very complicated, except for small mobility where the casing is plastic. If it is made of aluminum, as on some buses, the heat can melt it, revealing holes through which it would be possible to intervene. When the battery is under the chassis, or even inside, if the tires burst, the car ends up on its stomach and the pack becomes inaccessible ».

A very expensive solution: “ Drilling the casing of a battery requires sophisticated and expensive means. It works in the lab, but not in the field. A Cobra lance costs 300,000 euros. We cannot put this material in all the rescue centers. To use it, firefighters must be in contact with the battery, with possible flares of three or four meters and a significant electrical risk. ».

The best solution

Immersion, thermal blanket, perforating hydraulic lance: if all these solutions are not applicable on a large scale, how should emergency services intervene in the event of a fire in an electric vehicle? “ I advocate doing it the traditional way, as all the tests I have done have shown. If it is not effective, we let it burn while protecting the environment to avoid using 30,000 liters of water. Battery thermal runaway will stop on its own in 15 to 60 minutes ».

Universal solution: “ This involves intervening with two nozzles, one to extinguish the fire and the other to cool the battery in order to avoid thermal runaway and/or the tanks. It is applicable to electric engines or those running on hydrogen, LPG and CNG. Beforehand, there is a protocol to follow before intervening ».

On an EV, the approach is used to eliminate the electrical risk: “ Before trying to remove the occupants, the battery must be decoupled from the rest of the vehicle. This is done at the large orange cables. The problem is that there are currently 70 different protocols for working on electric and hybrid cars. They are provided by manufacturers as decision aids for emergency services. At Euro NCAP, we want to try to harmonize all of this ».

Fewer EV fires than VT fires?

It is accepted that the risk of fire is lower on electric cars than on thermal cars: “ There is still a lack of statistics in this area. However, two studies were carried out at the international level one or two years ago. The results coming to us from Australia indicate that there are no more fires in electric vehicles than in thermal vehicles. ».

In the United States, it is more vague: “ We are told that there are far fewer EV fires in proportion, but, at the same time, there would be many more problems with hybrids than with thermals. Which does not completely exempt electric cars. We can clearly see that there are some dramatic cases of spontaneous fire after accidents. When we know the results of the investigations, we will know whether or not there is a specific problem on this subject. ».

Can we say that a fire in a car equipped with an LFP (lithium iron phosphate) battery is less serious than if it has an NMC (nickel manganese cobalt) pack? “ That's great literature, a view of the mind. What is true is that an LFP battery is more complicated to cause thermal runaway. Then, it's the same, it's the same kinetics ».

The case of Belfort hydrogen buses

Last December, the fleet of the Optymo public transport network active in the Territoire de Belfort sector included seven 12-meter Van Hool A12 LF FC buses which were set on fire around 4:00 a.m. on Thursday January 2, 2025. The electric motor Each of these vehicles was powered by a fuel cell receiving hydrogen from five tanks installed on the roof for a total capacity of 40 kilos of gas.

Also at this level, the buffer battery with an energy capacity of 36 kWh. For comparison, it is less than the 44 kWh pack of a Citroën ë-C3. The safety devices having worked well, the hydrogen escaped from the tanks in the form of flares without causing an explosion. There was talk of a flash in the driver's seat of one of the vehicles, followed by a glow. The motor and its power supply appear to have been exonerated.

Does the architecture of the powertrain explain why the seven hydrogen buses were all destroyed in Belfort? “ It's not surprising to me that all the vehicles were caught in the fire, because they were parked next to each other with little separation. Under these conditions, the domino effect played out, as would have been the case with a diesel or CNG model. To reduce it, vehicles can be parked in threes or fours, the islands thus formed being, for example, separated by a space of four to five meters ».

Also readWhy are electric cars more likely to be hit from behind than thermal cars?

Thanks

Automobile Propre and I thank Lieutenant-Colonel Gentilleau (ER) very much for his welcome, his availability and his testimony that we requested.

For allowing us to get in touch with our interviewee, a big thank you also to Marc Mouthon, gas training facilitator (LPG, NGV, hydrogen), and expert volunteer firefighter. It is him that we see in firefighter intervention clothing in the illustration of the article. The photo was taken during a training course on the specifics of hydrogen that I attended at Energy Formation.

As a reminder, any derogatory contribution towards our interviewees, their lives, their choices, and/or their ideas will be deleted. Thank you for your understanding.