Tesla fire shows electrics face safety challenges

Oct 04, 2013 by Mike Baker
In this June 22, 2012 file photo shows a Tesla Model S driving outside the Tesla factory in Fremont, Calif. Shares of Tesla Motors are down another 5 percent as investors in the high-flying company assess the fallout from a fire in one of its $70,000 electric cars. (AP Photo/Paul Sakuma, file)

When debris on a Seattle-area freeway pierced the battery of a $70,000-plus Tesla Model S and touched off a raging fire, it raised new safety concerns for electric-vehicle owners.

It also caused rare jitters among investors, who of late have viewed Tesla as nearly invincible.

Electric vehicles have scored well in government tests of front and side crashes—the Model S earned the highest score possible. But Tuesday's incident demonstrates that real-world driving could reveal some vulnerabilities that don't show up in laboratory testing.

"The safety challenges related to are still in the early stages of being tested and addressed," said Karl Brauer, senior analyst at Kelley Blue Book.

Tesla said the Seattle-area driver hit a large metal object in the road, which damaged a cell and caused a fire. The company said the car acted as designed by containing the blaze in the front of the car.

Still, experts said Thursday that while incidents like this will happen again, they are rare. And electric cars still are safer than those with gasoline engines that haul around a tank full of flammable petroleum. The Tesla fire also shows that automakers need to bolster the shields around batteries, and that firefighters need more training to deal with electric car blazes.

Of the estimated 194,000 vehicle fires in the U.S. each year, the vast majority are in cars and trucks with gasoline or diesel engines. Electric vehicles make up less than 1 percent of the cars sold in the U.S.

Tesla says this is the only fire ever to happen in one of its batteries. Although a Chevrolet Volt made by General Motors caught fire two years ago after a government crash test, neither GM nor Nissan, which make the top-selling electric cars in the nation, know of any real-world blazes in their vehicles.

In this Tuesday, Jan. 15, 2013, file photo, George Blankenship, Tesla Motors Vice President, Worldwide Sales & Ownership Experience speaks at media previews for the North American International Auto Show in Detroit. An Internet video of a fiery Tesla electric car near Seattle helped to push down the company's stock price Wednesday, Oct. 2, 2013. (AP Photo/Paul Sancya, File)

"If you think about what you'd rather be close to, 10 gallons (39 liters) of gasoline or a battery pack, I'd pick the battery pack every day," said Giorgio Rizzoni, director of the Center for Automotive Research at Ohio State University, where he is a professor of mechanical and electrical engineering.

Still, an Internet video of the Tesla fire spooked investors and caused a sell-off Wednesday and Thursday. Tesla shares fell 6 percent Wednesday, and they closed Thursday down $7.64, or 4.2 percent, at $173.31.

At that price, Tesla's market value has dropped about $2.4 billion in the past two days. Still, if an investor purchased a share of Tesla at $35 on Jan. 2, they're sitting on a gain of nearly 400 percent. Tesla has dazzled Wall Street by selling more vehicles than expected and posting its first quarterly net profit earlier this year.

Deutsche Bank analyst Dan Galves, in a note to investors Thursday, said he expects bad news and investor concern to push down Tesla shares in the short-term. Investors, he said, will be concerned because electric cars represent a new technology with a high sensitivity to safety risks. But he wrote that the Model S has been collectively driven more than 83 million miles (134 million kilometers), yet this is the first fire despite 12 significant crashes and extreme testing by the government.

"We have confidence that this is an isolated incident that could happen to any vehicle," Galves wrote. He still thinks Tesla shares will reach $200.

Tesla said that on Tuesday the Model S warned the driver of problems from the collision. He pulled off the road, smelled smoke and saw flames. A company spokeswoman said the fire originated in a battery cell damaged in the collision, and the car's design prevented the fire from spreading to the rest of the battery and contained it in the front.

Thomas Habetler, an professor at Georgia Tech, theorized that the highway debris punctured a shield and a , causing a short-circuit, bypassing fuses and electrically linking one battery terminal to another. "You're going to have arcing and sparking in that case, which can cause whatever it is to light on fire," he said. Leaking battery coolant also could have caused a short-circuit, he said.

Habetler and Rizzoni said electric cars are designed to withstand blows from highway debris. Fires are so rare that this one shouldn't give anyone pause if they're considering one, they said.

"My feeling is this was a case of prodigious bad luck," said Rizzoni.

Tesla said it already has inspected the Model S. Galves wrote that the company's ability to monitor cars remotely should result in a detailed report on the cause. It was still unclear Thursday if federal safety regulators would look into the fire because of the partial government shutdown.

Capt. Kyle Ohashi with the Kent, Washington, Fire Department said crews learned lessons from fighting the Tesla . For one, the dry chemical extinguisher seemed to work better than water to combat the blaze. And he said the department is now aware that accessing the in a Tesla is quite difficult.

Explore further: Tesla shares fall further on Model S fire

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User comments : 21

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Bob_Kob
1.4 / 5 (14) Oct 04, 2013
I wonder how you prevent this. In a crash, the cells of the batteries will hit eachother causing a short - theres no way to stop this save making the battery indestructible.
triplehelix
1 / 5 (11) Oct 04, 2013
Put a lot of flame retardant/resistant stuff round the battery or in it's casing.

Even then you'll have horrible chemicals and nasty dangerous battery segments everywhere from the crash.

QuixoteJ
1 / 5 (9) Oct 04, 2013
But Tuesday's incident demonstrates that real-world driving could reveal some vulnerabilities that don't show up in laboratory testing.
There is an old saying that has soemething to do with an iceberg...
Grallen
not rated yet Oct 04, 2013
Yeah. The only issue is they are using old tech batteries(li-ion). there are better alternatives already on the market going forward.
xX_GT_Xx
3.5 / 5 (4) Oct 04, 2013
Headline: Tesla electric car catches fire. (Driver fine.)

Not the headline: On the same day elsewhere in the country, 90 people (average) died in gas powered vehicles. About twice as many injured.

If I was conspiracy minded, I would recall the fake "runaway Prius" story back in 2010. Managed to scare a few people out of buying Toyota, even though it only took a minor amount of scrutiny for the driver's story to fall apart.

cantdrive85
1.3 / 5 (12) Oct 04, 2013
Gasoline has never been known to catch fire or explode in such instances. Events such as this will however drive innovation and someone will develop a remedy.
Eikka
1 / 5 (10) Oct 04, 2013
"If you think about what you'd rather be close to, 10 gallons (39 liters) of gasoline or a battery pack, I'd pick the battery pack every day,"


Two things:

1) The electric charge of the Tesla battery is equivalent to 2½ gallons of gasoline, and it's filled with a flammable organic solvent which works as the electrolyte.
2) A battery fire is self-starting and self-sustaining until it runs out of reagents. It needs no outside air source to burn like a gasoline fire.

I'd rather pick the gasoline. At least getting a hole in your tank won't automatically cause it to light up.
Yelmurc
5 / 5 (2) Oct 04, 2013
Tesla Motors official response

http://www.teslam...l-s-fire
HeloMenelo
1.3 / 5 (12) Oct 05, 2013
"If you think about what you'd rather be close to, 10 gallons (39 liters) of gasoline or a battery pack, I'd pick the battery pack every day,"


Two things:

1) The electric charge of the Tesla battery is equivalent to 2½ gallons of gasoline, and it's filled with a flammable organic solvent which works as the electrolyte.
2) A battery fire is self-starting and self-sustaining until it runs out of reagents. It needs no outside air source to burn like a gasoline fire.

I'd rather pick the gasoline. At least getting a hole in your tank won't automatically cause it to light up.


Fuel leaking from the hole touching hot ice parts or getting a spark could light up, that's why there's been thousands of ICE car fires throughout history.

I'd rather pick the battery.Tesla designed the car so well, that the fire was contained not to spread, the same cannot be said for ICE vehicles.The car even warned that something was wrong, ICE car wont tell you if your tank explode.
Humpty
1 / 5 (10) Oct 05, 2013
Of the estimated 194,000 vehicle fires in the U.S. each year, the vast majority are in cars and trucks with gasoline or diesel engines. Electric vehicles make up less than 1 percent of the cars sold in the U.S.

OK put that crap into context - proportionally speaking, how many electric vehicles are there on the road, and how much distance are they actually covering, AND then how many fires are there?

I tend to think that the battery fires would remain contained in the battery area, instead of setting fire to the interior of the car as well.

Where as petrol fires tend to spread quickly and incinerate the entire car.

So me thinks electric is the way to go, plus some extra shielding around the batteries against most chunks of metal that can get thrown up against them.

antialias_physorg
not rated yet Oct 05, 2013
theres no way to stop this save making the battery indestructible.

If they're going to short then make sure to dump the electricity into something that can absorb a lot of heat (e.g. a block of copper). Or just do what Tesla did and make sure that the passenger area is reasonably safe from contact - even in a crash.
Of course there are always crash scenarios that will be worse than your crashbox can handle. But at those energy levels it doesn't make a difference whether you get smeared to a pulp or electrocuted.

Firefighters will need to adjust their techniques, though. But that has always been the case with new technology.

Not the headline: On the same day elsewhere in the country, 90 people (average) died in gas powered vehicles. About twice as many injured.

To be fair: There are a LOT more gas powered cars on the roads which unskews that comparison a bit.
Eikka
1.4 / 5 (11) Oct 05, 2013
Fuel leaking from the hole touching hot ice parts or getting a spark could light up, that's why there's been thousands of ICE car fires throughout history.


True, engine fires happen, but that's why the gasoline tank is usually at the back of the vehicle where it is protected from things like road debris. Perhaps it would be better to place the battery there as well.

I'd rather pick the battery.Tesla designed the car so well, that the fire was contained not to spread


Whether the fire spreads is irrelevant as long as the passengers get out of the car, because the car is totaled anyways. At several tens of thousands of dollars, that's a hard loss to a working family even without loss of life or injury: the loss of your car may even lose you your job.

I'd rather not have the fire happen in the first place, which is why I would not choose a car with a chemical firebomb built into its bottom.
Eikka
1 / 5 (10) Oct 05, 2013
The car even warned that something was wrong, ICE car wont tell you if your tank explode.


Gasoline tanks do not explode. They are physically and practically incapable of the same sort of combustion as lithium batteries, unless some prankster has filled yours with potassium nitrate to oxidize the fuel.

TheGhostofOtto1923
2.3 / 5 (3) Oct 05, 2013
Gasoline tanks do not explode. They are physically and practically incapable of the same sort of combustion as lithium batteries, unless some prankster has filled yours with potassium nitrate to oxidize the fuel.
They can and do 'explode' in a cinematic sense. An adjacent fire can heat the fuel above its flashpoint, and the sudden increase in pressure can rupture the tank making a very satisfying fireball.
http://www.youtub...gO1tRY_g
http://www.youtub...4h9vE720
https://www.youtu...2x60alY0
http://www.youtub...zND8aVSM

-Welding on tanks with vapor in them can also make them explode.
TeV
not rated yet Oct 06, 2013
Once again, Eikka seems bent on displaying his/her breathtaking ignorance and/or anti-EV agenda.

Tell me Eikka, what vehicle are you driving that gets 250 miles from 2.5 gallons of gas? That's equivalent to a 100mpg ICE car. The Tesla Model S gets an EPA rated 250 miles per charge, so your bias and lies are once again showing.

And while lithium ion batteries are very flammable when their casings are breached, Tesla HAS installed many safety systems to counteract that threat - from the computer warning, to firewalls within the pack to keep fires isolated to small areas, a chemical formulation that slows combustion, and even vent holes installed on the bottom of the pack (but not the top) to vent flames away from the passenger compartment in a fire.

All of which seem to have worked perfectly in this extreme example, BTW.

With 90 ICE fires a day EVERY day, EVs should combust about once every 11 days or so with 1% market share - but this is the first one in 4 years! Explain, Eikka.
kochevnik
3 / 5 (4) Oct 06, 2013
Correct me if I am wrong but it seems that Eikka opposes anything that isn't nuclear powered
Eikka
1 / 5 (1) Oct 25, 2013
Tell me Eikka, what vehicle are you driving that gets 250 miles from 2.5 gallons of gas? That's equivalent to a 100mpg ICE car. The Tesla Model S gets an EPA rated 250 miles per charge, so your bias and lies are once again showing.


Check your facts before berating other people.
http://hypertextb...ik.shtml
85 kWh in the battery divided by 8.76 kWh per liter, divided by 3.8 liters per gallon is 2.58 gallons equivalent energy. The fact that the electric car goes so far is because it uses 75-85% of the energy as compared to the internal combustion engine that ultimately manages to extract just 20-30%

Tesla HAS installed many safety systems to counteract that threat


Somehow I think it's just another Titanic waiting to happen. The fact is there's plenty of combustible material in the battery, and the chemicals necessary to start a fire.

Explain, Eikka.


I wouldn't expect a $100,000 car to be as shoddily made as the average car.
Eikka
1 / 5 (1) Oct 25, 2013
Correct me if I am wrong but it seems that Eikka opposes anything that isn't nuclear powered


You are wrong. I only oppose unwarranted hype and selective ignorance of facts and problems with technology because they don't jive with the person's utopias or political agenda. The reason you think me a nuclear proponent is because I tend to point out propaganda where I see it, and nuclear power gets a lot of it.

In actuality, I believe we're perfectly capable of doing without, but for some odd reason people keep getting angry when I explain to them what it would actually require. I suspect that's because they haven't really thought about what they're trying to do, because everyone's so keen on just throwing (other people's) money around to feel good about themselves.

Besides, aren't electric cars by definition running on nuclear power as far as there's any in the grid?
Eikka
1 / 5 (1) Oct 25, 2013
With 90 ICE fires a day EVERY day, EVs should combust about once every 11 days or so with 1% market share - but this is the first one in 4 years! Explain, Eikka.


-Teslas haven't been on the market for a very long time and the sales only picked up in the last year. They're all practically new with little wear and tear.
-Electric cars aren't doing the same number of miles per vehicle on the roads because they are limited in range.
-Electric cars are premium cars - they're not cheaply made.
-1% market share does not imply 1% share of total vehicles because it measures sales of new cars

In reality, there's about 25,000 Model S sold right now, and there's 253 million passenger vehicles in the US. That's one percent of one percent actual share.

As far as electric car fires happen, there seems to be a couple every year. The Volt caught fire, Fisker Karmas have caught fire, Citroen Berlingo EVs have caught fire... but no Toyotas or Nissans so far.
Eikka
1 / 5 (1) Oct 25, 2013
Other lesser known incidents have been BYD's and Zotye EV's battery fires in China, and Mitsubishi i-MiEV and Outlander PHEV batteries melting. When you start to dig further these things turn up, but nobody really talks about them because it's bad PR.

The thing is, there's not enough statistical information to determine whether electric cars with lithium batteries are safer in terms of fire because they've not been around for long enough in the present capacity. All the evidence however points out that they do catch fire and fairly regularily so. It's not until people start crashing and neglecting them that we see how much of a problem that will become.
Eikka
1 / 5 (1) Oct 25, 2013
There also seems to be a small epidemic of electric golf carts catching on fire and burning down peoples' houses. Just google for "electric golf cart fire".

But the issue with those seems to be more of a negligence of maintenance and hydrogen produced by flooded cell batteries catching fire, which is a traditional issue with lead acid batteries.