Use of electric car
Electric cars: Is the risk of fire increased due to the battery?
27.07.2024
Mobility operates 600 electric cars. Are you wondering if the risk of fire is greater than in the case of a combustion engine? Here you can find out why this much-cited prejudice is in fact misguided – and what to do if the worst comes to the worst.
Electric cars do not catch fire more often than vehicles powered by other technologies. This has been confirmed repeatedly by various specialist organisations in recent years. For example, the Swiss Fire Brigade Association that electric vehicles are basically no more dangerous than petrol or diesel vehicles. Almost identical to the words of the Counselling Centre for Fire Prevention, an initiative of the Association of Cantonal Insurance Companies for Buildings. It also attested to the “high level of safety of the vehicle systems” of the electric cars.
This is not surprising: The same provisions apply to a registered car, regardless of the type of drive, which stipulate the highest level of active and passive safety. In the Euro NCAP crash tests, electric and combustion versions of the same vehicle type always perform equally well. Likewise, many independent electric car models receive the maximum possible rating of five stars.
How often do electric cars and combustion engines catch fire?
Vehicle fires are rare for all engine types. The Swiss Insurance Association (SIA) does not keep separate statistics. The German Insurance Association (GDV) reported at least 12,000 passenger car claims resulting from fire or electrical short circuits in 2022, though the GDV does not differentiate according to engine type. 12,000 cases of 48.8 million registered passenger cars in Germany – that’s extremely low. According to the German Insurance Association (GDV), claims due to fires have actually continued to decline over the past decade – even though there’s been a significant increase in the number of electric cars.
So why do electric cars that catch fire still make headlines? There are presumably two reasons for this:
Firstly, there are still far fewer electric cars than cars with combustion engines – and media attention tends to be focused on what is exotic and new.
On the other hand, electric cars burn for quite a long time when the traction battery catches fire.
In addition, pictures and videos of vehicle fires are shared on social media and commented on as evidence of the “electric car risk”. In the event of a precise Research these turn out to be fires without the involvement of an electric car.
How well are electric cars protected against fire?
Electric cars are just as well protected against fire as cars powered by a combustion engine, otherwise they wouldn’t have been approved for use. When an electric vehicle catches fire, the traction battery is usually not the cause of the fire. The greatest fire risk in cars is posed by the plastic components and the tyres. Plastics are used in a whole range of different ways in modern vehicles – for insulation, seat covers, dashboards and panelling, for example. Tyres have also become bigger and wider over the years. This applies to both electric cars and cars powered by a combustion engine.
Like the fuel tank in a car with a combustion engine, the drive battery in an electric car is located in a crash-proof zone. The fuel tank is located in the lower rear section of the vehicle, while the drive battery is positioned in the substructure of the chassis. This reduces the likelihood of battery damage in the event of an accident. It is also housed in a waterproof metal housing.
In the Euro NCAP crash tests and in the crash tests of the ADAC (Allgemeiner Deutscher Automobil-Club), an electric car has never caught fire and no battery pack has ever been damaged. Even in the case of joint Crash tests the testing organization Dekra and the University of Göttingen under more stringent test conditions. despite the fact that the cars tested looked in a fairly bad state afterwards.
As a safety measure, electric cars automatically cut off the power supply to the drive battery in the event of a serious rear-end collision. This protective mechanism is activated when an airbag is triggered, for instance. There are “rescue cards” for emergency services, which show where the high-voltage battery can be disconnected.
It is, of course, true that the traction battery can also start to burn: If a vehicle is on fire or the impact was so severe that the traction battery or its housing has been damaged. Then it is quite possible that a high-voltage battery can burn for several days.
But it is also a fact that most electric cars on Swiss roads are still quite young. The risk of fire increases with age, as the materials (particularly plastics) become brittle and short circuits are more likely to occur. This is not the only reason why regular maintenance is important – as is the case with a combustion engine car.
What should I do if an electric car catches fire?
In the event of an emergency, the same rules of conduct apply as for combustion engines:
Keep a safe distance: You should get out of the vehicle as quickly as possible. However, there will still be enough time to remove injured people from the car.
Secure the scene of the accident and raise the alarm: The most important thing is to secure the scene of the accident and alert the fire brigade. When doing so, it is helpful to indicate that the vehicle on fire is an electric one so that the emergency services can plan accordingly.
Opinions differ as to whether it makes sense to attempt to extinguish the fire yourself with a powder extinguisher – in the event of a fire in the motor compartment, for example. Non-experts usually have little experience of this and the quantities of extinguishing agent people have available to them will usually be too small. In any case, you should not expose yourself to any unnecessary risk when attempting to extinguish the fire. For example, it is important not to touch high-voltage cables – not even indirectly, for example by pointing a jet of water at them, because this can conduct electricity, too.
Good to know: by way of a warning, all high-voltage cables in an electric vehicle are sheathed in orange. Hands off!
How do the fire brigade put out the flames on an electric vehicle that has caught fire?
How the fire brigade proceeds depends on the location of the fire. For example, if there is a fire in the motor compartment, the fire is smothered with extinguishing foam – in the same way as with a combustion engine. If it is obvious that the drive battery is already on fire, the only thing to do is to apply large quantities of water. If the drive battery is on fire, the fire brigade doesn’t use the water to extinguish the flames but only for cooling purposes. They will continue to do so until there are no more uncontrolled chemical reactions as a result of the heat. Traction batteries contain a lot of energy, so this process can take hours. Above all, the fire brigade must ensure that the fire does not subsequently reignite. This can be monitored by means of thermal imaging cameras, for example. In extreme cases, an electric car has to be temporarily stored in a fireproof, water-filled container or bag. This last resort almost inevitably results in the car being a total write-off.
According to the Swiss Fire Brigade Association local fire brigades have been trained for more than 20 years on the special features of electric cars in firefighting and recovery.
Do I have to pay attention to anything when parking with electric cars in underground car parks?
The short answer is no. From the point of view of insurance companies and expert organisations, there is no reason to ban electric cars from entering underground car parks. The Empa, a research institute at ETH Zurich, conducted tests with burning electric cars a few years ago in order to assess the risk to multi-storey car parks and tunnels. This was done on behalf of the Federal Roads Office. Result: The heat generation is no more dangerous than with an internal combustion engine. The pollutant emissions may differ, but they are just as dangerous as those of a diesel or petrol engine that is on fire. What’s more, modern tunnel ventilation can also handle the emissions of a burning electric car.
What will fire protection in connection with electric cars look like in the future?
Current electric vehicles already meet the same level of fire safety as combustion engines. With regard to traction batteries, however, the industry is carrying out research into new monitoring methods. For example, complications in one part of the battery are to be detected at a very early stage and corrective measures are to be taken automatically.
The chemistry of traction batteries could also change in the medium to long term. Today, most of them are lithium-ion batteries. The motivation behind developing such alternative chemistry is the prospect of being able to reduce costs and increase range. But a solid-state battery would be more flammable than is the case with the chemistry of today’s traction batteries, for example.