EV BASICS 1O7: Are electric vehicles safe in case of crash & fire ? | Preventive measures


The market is fast shifting from traditional gasoline engines to electric cars. But, are we moving to something that is safer than what we are used to? This doubt is quite natural to a common vehicle driver; but pity is that is often being ‘fuelled’ by many unreasonable rumours.

This article may help to separate those ‘rumours’ from the facts, In addition, may also briefly explain  What happens when an electric car crashes? ➤ How do the internal circuits and batteries react in an accident? ➤ How high is the risk of a fire in electric vehicles? ➤ How does an electric vehicle catch fire?

Above all, 
➤ as a driver what should you do to prevent fire accident? ➤ How should fire departments and rescue responders safely handle emergency situations? – with links to official guides from the EV manufactures.

Electric cars’ safety during crash:

Electric vehicles has the natural ability to achieve high safety standards – simply due to their electro-mechanical structure.

➤ The electric motors are much smaller than a combustion engine and are located directly on the axis. Also, the heavy batteries placed under-body of the vehicle, provide optimal centre of gravity and therefore very good road holding. (check 2:34 in the video below)

➤ Battery electric vehicles such as Tesla which have no engine on the front zone provide significantly larger empty space that spares the shock of a front collision.

➤ Other passive protection systems (such as air bags, seat geometry and restraints...etc) can also be well positioned to ensure a higher occupant protection score.

➤ Comparatively, it is easier to implement "active protection systems" such as automatic emergency braking systems (AEB) and lane support systems for superior collision prevention.

Below video may clearly explain the structural advantages of electric vehicles that helps in a safe crash in different scenarios.

(!) For those who may think that only expensive electric vehicle such as Tesla can ensure that high level of safety, may go through the safety tests performed on one of the smallest & cheapest electric vehicles – Volkswagen e-Up!, in comparison to its direct pear VW Up! (Petrol) , by ADAC - renowned automobile association in Germany.

The crash structures created are identical in both the vehicles and the after collision results clearly shows that the Volkswagen e-Up even with its additional weight of the batteries, there is no loss of safety. The vehicle structure has no higher deformation values and the load values ​​for the passengers are identical to those of the petrol-powered up! variant. The safety of the high-voltage system and the vehicle batteries was guaranteed at all times.

Electric cars’ safety concerning fire:

Critics often highlight the Li-Ion batteries of electric vehicle as a major source of risk. It is true that, the liquid electrolytes inside the Li-Ion batteries can overheat due to prolonged exposure to wrong conditions; or due to aging . There is also a chance of short circuit among the battery cells. Both these scenarios (overheat & short circuit) can catch up fire.

Battery management systems (BMS) inside the electric vehicles continuously monitor and regulates all the possible causes of fire. In case of any issue that can induce fire, these BMS completely cuts-off the battery power from the high-voltage components and cables of the car.

Even in the rare event of an fire, electric vehicles battery packs catch fire at a much slower rate than a fire that is fuelled by gasoline fuel.

Passenger compartment in the EV is isolated from the battery pack high voltage section by a multi-layer firewall. For example, Tesla batteries are fully isolated with an under-body titanium cladding and active cooling system. Thus, there is less chance of fatal injuries or loss ; when comparing with the highly inflammable gasoline, Li-Ion batteries in the electric vehicles pose less risk.

How to prevent fire in electric vehicles?

Though the electric vehicle design & manufacturing takes extreme care to prevent incidents, and every vehicle goes through stringent safety requirements before arriving at the showroom, in the end, the EV driver must take care a few items.

1. Electric vehicles need less, but periodic maintenance: When comparing with a gasoline car, the electric vehicles have much fewer moving parts, thus requires very low maintenance. However, the battery, electric motor, and related electronic components require periodic maintenance as suggested by the EV manufacturers.

2. Use only qualified (CE / FCC or equivalent) charging stations installed by qualified electricians: In case of home charging, the stations must be installed via necessary protection switches (RCCB); and in case of semi/- public stations the charge point operators have the obligation to periodically check various fault conditions of the infrastructure.

3. Go through the safety manual & always keep it in a reachable location for the rescue workers: Mechanical construction and battery arrangement of every vehicle is different, so the manufactures always give clear instructions to the rescue teams on what to do, how to dismantle, what tools to use in case of an emergency.

P.C: ADAC - Allgemeiner Deutscher Automobil-Club

Below links will take you to the safety instructions page of some popular EV model / makers. Now, all the manufacturers offer the standardized emergency cards for download. If you search “Rescue card / manual”, you can find the official instructions of almost every EV in the market.

➤ Tesla Model S, X and Model 3 : links here
➤ Audi e-tron: link to rescue card here
➤ Nissan: Rescue Data Sheets
➤ Jaguar: Rescue Data Sheets
➤ Honda: Rescue Data Sheets
➤ Hyundai: Rescue Data Sheets
➤ Toyota: Rescue Data Sheets
➤ Volvo: Rescue Data Sheets
➤ VW: Rescue data sheets (under "Further information for emergency services")

Having said that, no prevention mechanism is 100% safe. What to do when there’s an unfortunate incident of fire? You may read this follow-up post: How to extinguish electric vehicles fire (video)., which explains the step-by-step procedures followed by the professional fire fighters across the world.

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