Why do electric cars take fire

Often publicized because of impressive images, the fires of electric cars are fortunately very rare. But why can an electric car take fire, and why the fire is so tenacious ? Answer in this article.

Electric cars: why are they taking fire and you have to worry about it ?

Lithium-ion batteries do two things very well: they fuel a wide range of devices, smartphones with electric trucks, and they burn well. We explain this phenomenon to you, why it is to be put into perspective and what is done to remedy it.

Marc Zaffagni with Cnet.com

Posted on 12/12/2022 at 7:00 p.m. | Updated on 12/12/2022

Lithium-ion batteries have invaded all the hidden hidden homes, our pockets and our roads, but are also perfect fire warms. The liquid solution they contain is highly flammable at room temperature, the inner part of the battery called cathode is a source of oxygen, and if the internal parts of the battery come into contact, they heat up quickly and enough for ignite. Air transport regulators and the main maritime companies have enacted very strict rules concerning the transport of these batteries.

Large titles little glorious

The Big Bang of awareness of fire from Lithium-ion batteries was the Samsung Galaxy Note 7 case, which was prohibited in commercial flights in 2016. In the United States, electric car fires regularly make headlines. It happened several times with Tesla models but not only. Last year, the Chevrolet Bolt was forced to park outside and away from other cars while General Motors was solving a battery fire problem. Today, scooters and electric bikes make the headlines while some collective buildings prohibit them and the New York Municipal Council is considering new rules to ban the use of used lithium-ion batteries.

Still across the Atlantic, the Consumer Product Safety Commission has identified 25,000 cases of lithium-ion batteries that have seriously overheated between 2017 and 2021, not to mention cars and other vehicles, which do not fall under its competence.

What triggers a battery fire ?

According to the occupation Safety and Health Administration, the lithium-ion batteries generally burn when one of the following four situations occurs:

• An incorrect load;
• Excessive solicitation of the battery;
• Battery swelling and rupture due to poor design, manufacturing or load;
• Physical damage which causes uncontrolled contact between the internal parts of the battery.

Unfortunately, most of these problems escape user’s direct control. Only the prevention of physical damage is a factor on which we have taken.

How to turn off an electric car on fire

Professional firefighters say that the management of an electric vehicle on fire is actually quite simple: they use a lot (and often a lot) of water to contain the fire, let the battery be consumed by itself and keep the carcass of the isolated car for several days in case the remaining cells are turned on, which is not uncommon.

There are extinction covers that block oxygen used for car fires, but they have little effect on an electric vehicle fire because the battery is in the chassis and is self -calibrated in oxygen.

A problem to put in perspective

Car fires are legion, about 500 times a day in the United States, and it is rarely electric cars. Indeed, the latter have sophisticated thermal management systems whose petrol cars do not have the equivalent in their fuel supply circuit. Let us add that electric vehicles are at the start of their development curve of these devices while thermal cars have largely exhausted all possible improvements. We can therefore assume that electric vehicles will become safer in the medium and long term.

The future of the lithium-ion battery

Lithium Ion is a nipper name that includes combinations using nickel, manganese, cobalt, aluminum, iron and other minerals and metals. One of the most interesting is a variant of lithium ion called lithié iron phosphate (LifePo4). A recent test conducted by the American Federal Aviation revealed that this formulation produces the lowest rise in temperature of the types of lithium ions during thermal runaway and that it is less likely to ignite the adjacent cells.

Ford is one of the car manufacturers that adopt the lithié iron phosphate combination because it allows you to manage many load cycles with low capacity loss and uses a cheaper, more abundant and less toxic basic material, both on the Political chemical plan. The drawback of these batteries is that they tend to be a little heavier and to have lower energy density than other formulations, which requires a larger amount of cells to obtain the same autonomy.

The other potential advance in battery safety could come from solid batteries, which eliminate most or all of the flammable material contained in current lithium-ion batteries. According to a recent study by the Sandia National Labs, the solid state batteries seem to be much safer, even if they also burn when they are pushed beyond the reasonable limits.

Fire safety of batteries is important because it is on it on which our perception of the safety of cars, scooters and electric bikes depends when we use them and the stoves.

Read also

Why do electric cars take fire ?

Often publicized because of impressive images, the fires of electric cars are fortunately very rare. But why can an electric car take fire, and why the fire is so tenacious ? Answer in this article.

Car fires are, in the majority of cases, volunteers, but they can sometimes also be accidental and due to dysfunction. Often, following a fire, when the car is recent, the manufacturer investigates and organizes a recall campaign if the fire results from a manufacturing defect.

With the emergence of the electric car in recent years and the many questions that revolve around a technology which, casually, remains quite “new” compared to thermal cars, incidents, and in particular fires concerning them, do the fatty cabbage of the specialized press. You can cite the fire of the car in the summer of 2022 in Gironde, which was due to an electrical defect … of a thermal van ! Or the Hyundai kona with a battery a priori defective.

Many items highlight this or that electric car (often Tesla, since they have long been “alone” and numerous on the electric cars market) prey to a fire.

As a result, in the collective imagination, and it is completely normal, we have regularly heard, wrongly, ” that an electric car is more likely to set fire than a thermal“” . To make sure that nothing, These fires are often impressive and violent, given the fact that lithium-ion batteries are very energy dense. This therefore leads to a long and persistent fire, forcing the fire soldiers to face stubborn and spectacular lights. Below, here is for example a tesla Model S sets fire, and it has nothing to do with that of a thermal car.

This content is blocked because you have not accepted cookies and other tracers. This content is provided by YouTube.
To be able to visualize it, you must accept the use being operated by YouTube with your data which can be used for the following purposes: Allow yourself to view and share content with social media, promote development and improvement of products D’humanoid and its partners, display you personalized advertisements in relation to your profile and activity, define you a personalized advertising profile, measure the performance of the advertisements and content of this site and measure the audience of this site ( more)

How does an electric car fire intervene ?

For a thermal car, the causes of a fire can be multiple. In the majority of cases, this follows a road accident, while manufacturing defects and bad repairs arrive respectively in the second and third position. This can thus lead to fuel leaks, failures of the electrical system, an important heat source (overheating of the engine, etc.), a catalyst problem ..

As you are surely without knowing it, Electric cars are technically less complex than thermal cars (absence of many fluids, complexes of gearboxes, highly flammable elements, etc.), thus, they should be less subject to fires. But we will come back a little lower.

Nevertheless, what can make an electric car set for fire ? As with thermal models, the reasons can be multiple, but they are generally very different. The deterioration of wiring and batteries are generally the most exposed elements that cause the fire of an electric car. 100 % electric cars being in the majority of very recent cases, these concerns do not yet concern them.

The most frequent risks on a new car concern batteries, especially often due to overload and high temperatures. But there again, These are manufacturing defects in the majority of cases where overload and high temperatures are only aggravating factors. Most battery defects are attributable to suppliers rather than manufacturers.

Identifying the source of a fire of a car, thermal or electric, is generally very complicated since the car is generally completely calcined and the traces of the origin of the fire have disappeared.

Why are the lights so stubborn ?

What explains the media coverage of these fires is indeed because of the “novelty” effect of the electric car, but also certain very virulent groups which hate the electric car and take the opportunity to highlight this type of problematic. But the main reason for this media coverage is mainly because These fires are sudden, stubborn and very impressive.

Some even compare electric car fires with those related to gas. Recently, a video of the fire of an electric bus in Paris has toured the web, especially because the images were quite impressive. Electric car lights are very complicated to turn off for firefighters, these models being their own fuel source, They can burn for hours and be difficult to cool.

This content is blocked because you have not accepted cookies and other tracers. This content is provided by YouTube.
To be able to visualize it, you must accept the use being operated by YouTube with your data which can be used for the following purposes: Allow yourself to view and share content with social media, promote development and improvement of products D’humanoid and its partners, display you personalized advertisements in relation to your profile and activity, define you a personalized advertising profile, measure the performance of the advertisements and content of this site and measure the audience of this site ( more)

Thus, even when a fire seems to be extinct, He can get reluctant quickly, And this is why firefighters are now trained in the extinction of fires concerning vehicles with batteries (hybrid and electric). A few years ago, Tesla had even prepared a guide prepared for first aid. In the same spirit, General Motors has also set up, in Canada and the United States, training for first aid in the event of a fire of an electric car.

A new challenge for firefighters

Electric cars do not burn like thermal cars. This is notably the firefighters not seen so long ago on the Sacramento side following the fire of a Tesla Model S: 17,000 liters of water were necessary to extinguish the fire and a mini-basin was formed to immerse the electric batteries. In its report, Tesla indicates that it is generally necessary Between 11,350 liters and 30,300 liters of water to turn off the fire from an electric car.

Batteries can also take fire again Several hours, or even several days, after the initial incident, Because of a so-called “thermal runaway” phenomenon that can occur in damaged lithium-ion batteries. Also according to the American manufacturer, it is recommended to monitor the temperature of the batteries for at least 24 hours after a fire.

The manufacturers are now obliged to publish a guide for first aid for each model they produce, but the American agency responsible for investigating transport accidents (NTSB) recently specified that only eight manufacturers out of the 22 concerned had completely integrated its recommendations.

Do electric cars burn more than the others ?

As stated above, with the media coverage granted to burning electric cars, one might think that they are more subjected to fires. But what about it in fact ? Difficult to have a step back, since the electric car is still recent, but a recent American study seems to undermine received ideas.

Indeed, the insurer Autoinranceez Associate several thousand data of three different sources to take stock of the most risky vehicles. The three sources in question are the NTSB, the office of transport statistics and the central American central recall file.

And the data is quite edifying, since the insurer, after having overlooked the official registration data with the number of fires identified by the administration, whether on accidents, but also “spontaneous” fires, the category of cars most sensitive to fires would be that of hybrids. The insurer thus highlights a rate of 3,457 fires per 100,000 vehicles, in front of the thermal (1529) and electricity (25) (25). This is not absolute value (because 3.457 % of hybrid cars that would take fire, it would do a lot …), But a fire rate.

Generally, in the event of a risk of fire, the manufacturers are very reactive and set up fairly large recall campaigns. For example, Hyundai had to recall 82,000 Kona Electric some time ago for a battery problem.

More recently, it was Chevrolet who was talked about in the United States with his bolt. General Motors, the mother-in-law of Chevrolet, thus advised the owners of certain Bolt EVs in mid-2010 not to park them inside or load them unattended during the night, all before initiating a reminder of his vehicle. After investigation, defects on batteries manufactured by LG could, in certain circumstances, trigger fire starts.

The French insurer AXA confirms the information, based on the accidentology figures: an electric car has no more chance of taking fire than a thermal car (petrol or diesel).

The future of Numerama is coming soon ! But before that, our colleagues need you. You have 3 minutes ? Answer their investigation