What Happens When EVs Catch Fire? Spoiler Alert – It’s Not Good

Electric vehicles (EVs) catch fire at a much lower rate than their petrol-powered cousins, but when it happens, the results can be catastrophic. An EV ignition requires firefighters to deploy methods that are extreme, expensive – even dangerous. When a Tesla truck recently ignited on a US highway, the blaze needed 50,000 gallons of water and an aircraft used for quelling forest fires before it eventually died out.

As EV adoption grows and more imports arrive from overseas, how worried should drivers and fleet managers be?

We examined what’s causing plug-in electric vehicle fire incidents and asked what manufacturers are doing to ensure EVs and their troublesome lithium-ion batteries don’t become an industry-exploding problem.

Table of Contents Table of Contents

1. Key Takeaways
2. Why Should We Care About EV Fires?
3. Why Do Electric Cars Catch Fire?
4. Why Are EV Fires So Hard to Put Out?
5. What Is the Industry Doing About It?
6. Reality Check: How Often Do EV Fires Occur?
7. What to Do if Your EV Catches Fire
8. The Bottom Line
9. FAQs
10. References

Show Full Guide

Table of Contents

1. Key Takeaways
2. Why Should We Care About EV Fires?
3. Why Do Electric Cars Catch Fire?
Show Full Guide
4. Why Are EV Fires So Hard to Put Out?
5. What Is the Industry Doing About It?
6. Reality Check: How Often Do EV Fires Occur?
7. What to Do if Your EV Catches Fire
8. The Bottom Line
9. FAQs
10. References

Why Should We Care About EV Fires?

This past August, a Tesla Semi truck crashed en route to the company’s battery gigafactory in Nevada, unleashing an inferno that took multiple teams of emergency services workers 14 hours to extinguish.

California’s Interstate 80 had to be closed while firefighters dumped 50,000 gallons of water on the burning wreckage and called in a water bomber filled with flame retardant to stop the flames from spreading.

Temperatures reached a reported 1,000 Fahrenheit (537 Celcius). The smoking wreckage then had to be transported to a safe facility and kept under observation for 24 hours to ensure it didn’t reignite –?a recurring issue with fires involving EV batteries.

Earlier in August, an electric vehicle (EV) explosion in a South Korean car park damaged more than 800 cars and caused water and power outages. An unplugged Mercedes-Benz EQE 350 spontaneously combusted in Incheon, west of Seoul, requiring evacuation of more than 200 families from the apartment complex above. Temperatures reached a reported 2,700 Fahrenheit (1,500 Celsius) and took firefighters eight hours to extinguish. Twenty three people were hospitalized.

And alongside people and property, EV fires hammer the environmental too. Plug-in electric vehicle fire incidents typically need massive quantities of clean water to keep them under control, which can be contaminated by toxic chemicals and runoff into the water table.

Why Do Electric Cars Catch Fire?

The Tesla incident followed two others, prompting an investigation by the US National Transportation Safety Board (NTSB) into the potential hazards posed by EVs’ lithium-ion batteries.

It concluded that electric vehicles “pose the risk of electric shock to emergency responders from exposure to the high-voltage components.” A further risk is that damaged cells might undergo uncontrolled increases in temperature and pressure, creating a “thermal runway” where the battery enters a rampant, self-heating state.

EV batteries have a Lego-like construction. The opaque rectangular units installed under the passenger area of a Tesla or BYD are composed of multiple smaller batteries called cells.

Why does it happen? Whether it’s automobile battery arrays or exploding Samsung phones, lithium-ion batteries can have issues. Manufacturing defects are one potential source of ignition, while a car crash will obviously expose the wiring and cause ruptures in the housing where each cell’s electrolytes are held. If a cell experiences a short and electrolytes are exposed to heat, they start to evaporate and form a gas. When the temperature rises to the right level, the gas explodes and spreads the fire to other cells.

Still, investigators often struggle to pin down the exact causes when EVs ignite. A review of EV fire investigations by EV FireSafe found that a ‘notable portion’ remained unidentified due to ongoing investigations or lack of detailed reporting.

In August, Jaguar advised about 3,000 owners of its 2019 I-Pace SUV they should park their vehicles outside because of fire risk from a manufacturing defect in their South-Korean made lithium-ion batteries.

Why Are EV Fires So Hard to Put Out?

The problem with lithium-ion batteries is they burn hot and burn slow.

Firefighters talk about the fire triangle needed to set off an ignition. Flame needs a fuel source to power it, a spark to set it off, and oxygen to keep it burning.? Lithium-ion battery arrays are designed to store energy, meaning fuel is always on hand. And despite being located in a protected area of the vehicle, a collision can provide the spark and let in the oxygen needed to complete the triptych.

The practical result is that firefighters often move the car’s burnt-out husk to a safe facility for observation, keeping vigil for at least 24 hours after the initial all-clear.

Adam Barowy, a lead research engineer at the Fire Safety Research Institute (FSRI), wrote in a recent blog post:

“We know now that traditional fire suppression approaches aren’t as effective on electric vehicle fires as they are with internal combustion engine vehicles. A better understanding of EV fire behavior will beget more effective fire fighting approaches, lest safety become an impediment to electric vehicle adoption.”

Knowing the signs and triggers of a potential re-ignition is one reason why US fire departments are re-training their teams to handle the particular risks of EV fires and the techniques needed to put them out. In the UK, some fire services are creating their own EV experts in anticipation of more frequent EV fires.

In the worst cases, experts at the International Association of Fire and Rescue Services (CTIF) recommend that burning EVs be fully submerged into a water filled container, though they acknowledge there are practical challenges that would need to be overcome –?not least the time required to fill a car or truck-sized container with water.

What Is the Industry Doing About It?

Electric vehicles of all sizes come equipped with battery management software that keeps tabs on the different cells packed into an EV battery. The software monitors performance and looks for indicators that a battery might be vulnerable to malfunction.

Manufacturers are also counting on solid-state technology to make EV batteries even more reliable.

The lithium-ion batteries in use today rely on liquid electrolytes to moderate the energy flow between their electrodes. As the name suggests, solid-state batteries use a solid electrolyte. That makes them more resilient against high voltages, extreme heat or sudden temperature changes. It also gives the battery more energy density, meaning they weigh less and deliver more mileage between charge-ups.

Lawmakers have also taken note. In Korea, the car park fire incident led to a number of new initiatives, including the adoption of a certification program for EV batteries. Seoul’s city government has also passed a new bylaw that should dissuade EV owners from overcharging their cars in underground parking garages.

It’s also compelling automakers to be more transparent about who makes the batteries running their EVs. Earlier this month, the South Korean government said it would make that a requirement.

Reality Check: How Often Do EV Fires Occur?

A March 2024 report by the International Council on Clean Transportation (ICCT) found that there has been a measurable rise in EV fire incidents over the past decade, corresponding with the rapid expansion of EV adoption worldwide.

South Korea saw a 200% increase in EV fires last year, with 72 fires versus 24 reported in 2021.

An analysis by the BBC found that there were 59 electric vehicle fires in 2022-23 across England, up from 30 in 2021.

Despite what looks like a surge in percentage terms, the real numbers are pretty small. A 2022 analysis of NTSB data by the insurance website Auto Insurance EZ found that EVs caught fire at a rate of 25 per 100,000 sold compared with 1,500 per 100,000 gas cars sold.

Across the Atlantic, a report by Sweden’s National Authority for Social Protection and Preparedness tracked EV fires in the country and compared them to ICE vehicle fires. For the period 2018-2022, on average, it found just 16 EV fires out of 3,400 passenger vehicle fires each year, meaning EVs account for 0.4 percent of all passenger vehicle fires annually.

Alexander Tankou, a researcher at ICCT, wrote:

“Existing data and literature indicate that EV fires are rare but could become more frequent as the EV stock grows and ages.”

What to Do if Your EV Catches Fire

An advisory from the US National Fire Prevention Agency says drivers should do the following if their EV catches fire mid-journey:

The Bottom Line

EV fires can be catastrophic, expensive, time-consuming, environmentally damaging, and require a lot of resources to handle. The good news is that they happen rarely. Social media is buzzing with frightening images of flaming cars and helpless firefighters. But the reality is that there is no epidemic, at least not yet.

With evidence of slowing EV sales, automotive marketing teams are more than aware of the reputational risks that could further threaten revenues. Battery engineers, meanwhile, are on the case, fine tuning battery management systems and working to perfect solid state technology. Even the relatively small risk of EV battery fires may soon be damped down.

FAQs