Hybrid and all-electric vehicles are increasingly commonplace in Santa Clara County, with a Tesla car, a Nissan Leaf or a Toyota Prius around every corner. And with the pervasiveness, emergency responders now have to size up a new possibility: what if one of them catches fire?

Last Friday, Mountain View fire crews had to tackle the problem directly, when an electric car battery overheated to temperatures of about 500 degrees and emitted a dangerous plume of smoke. The car, parked in the first block of E. Evelyn Avenue, had been converted for an internal combustion engine to all-electric, said Mountain View Fire Department spokesman Lynn Brown. The overheating likely resulted from thermal runaway, which can happen in a lithium ion battery for a range of reasons, including defects or improper use.

Brown said this is the first time he could remember local firefighters responding to an emergency related to an electric vehicle battery. Firefighters blasted the battery with carbon dioxide extinguishers, which Brown said served a dual purpose of both cooling down the battery as well as reducing oxygen that might fuel a fire in the battery. After emptying “several” extinguishers, fire crews were able to get the battery down to a still-piping hot 250 degrees.

After the battery stopped giving off smoke, Brown said the car was cordoned off in a safe location and the owner stayed overnight with the vehicle in case the battery began overheating again. Mountain View police officers frequently returned to the site that night to ensure that the vehicle was in a stable condition.

During the incident, fire crews were told not to use water to cool down the battery, based on information from the department’s materials safety data sheet, and were told to exercise caution to avoid getting shocked, Brown said.

“The lesson here is really to be careful with batteries,” Brown said. “They are a little different than your standard internal combustion engine.”

There’s been steady interest over the last seven years by first- and second-responders for training to deal with electric vehicles in case of a fire, according to Andrew Klock, senior project manager at the National Fire Protection Association (NFPA). The association offers training programs, mostly online, on how to deal with various car batteries if they catch fire or overheat, and has since trained over 200,000 emergency personnel throughout the country.

Although the carbon dioxide extinguishers worked on the car battery in Mountain View, Klock said the association advises using water to put out vehicle fires, regardless of whether it’s an internal combustion, hybrid or all-electric car.

“Water is the standard agent for vehicle fires, we don’t recommend anything else,” he said.

In one training exercise, the NFPA set seven high-voltage batteries on fire, including lithium ion and nickle-metal-hydride batteries, in mock cars and had fire fighters put them out with water. In all instances, it was totally acceptable and safe. The only caveat to that, Klock said, is that it can take thousands of gallons of water over a long period of time to bring the battery down to a safe temperature, meaning fire crews will need a sustained water supply from either a hydrant or two trucks full of water.

“If you can’t establish a sustained water supply, there’s a high likelihood the battery will reignite,” Klock said. “You won’t be doing any good if you don’t have enough water to cool down the battery and extinguish it.”

The threat of re-ignition goes well beyond when fire crews leave the scene. Similar to trick birthday candles, a lithium ion battery can catch fire hours, days or even weeks after it has been brought down to a normal temperature.

Alternative fuel vehicles have become ubiquitous over the last decade, with an estimated 3.2 million hybrid and electric vehicles on U.S. roads in 2014, according to the NFPA website. Data on vehicle fires shows that these high-tech vehicles are no more dangerous to emergency responders or the public than a normal internal combustion engine, but training and experience handling electric vehicle fires has lagged behind the surge in popularity.

“There’s a car fire in the United States every two minutes, but if a Tesla or a Nissan Leaf catches fire, you’re going to see it on tonight’s news,” Klock said. “This is new technology, not more dangerous technology. We just need to train or first- and second-responders how to deal with these new vehicles.”

Kevin Forestieri is the editor of Mountain View Voice, joining the company in 2014. Kevin has covered local and regional stories on housing, education and health care, including extensive coverage of Santa...

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9 Comments

  1. Note that the car in question was a conversion to electric propulsion, not a production electric car.

    Klock is right that gasoline powered vehicles often catch fire, but production electric vehicles rarely do.

    We do need to train first responders how to deal with emergencies involving electric vehicles, but there are far fewer of such emergencies, even proportionately to number of vehicles or vehicle miles travelled.

  2. Classic. The discussion on the “Gunn staff address conflicts following MLK Day talk” article has been closed for further discussion”.

    As a previous poster pointed out, “We have both in Palo Alto now: effective censorship on conservative or libertarian ideas, and official endorsement of progressive stances.”

    To @Open, I would love to respond to your post however it appears my views are shut down.

  3. Wow, not only that but the discsssion on the “Stanford University issues international travel warning” has been closed for discussion as well. With only three comments, nothing even remotely close to objectionable on either side. Why is this that thread closed? Are you afraid people just might be hearing more truth than the misrepresented info that most news I see reporting?????

    What is with all this censorship? Do you people not see the bubble you’re in?

  4. “Note that the car in question was a conversion to electric propulsion, not a production electric car.”

    That is beside the point. The physics of overheated Li-ion battery packs do not depend on when they were installed in the vehicle.

    “Klock is right that gasoline powered vehicles often catch fire, but production electric vehicles rarely do.”

    The proper statistic is incidents per vehicle per year. There are relatively few electric vehicles on the road due to their novelty, thus their apparent occurrence of fires is very low. But they are definitely prone to mishaps, including “spontaneous” as well as accident-related fires https://en.wikipedia.org/wiki/Plug-in_electric_vehicle_fire_incidents.

    Also bear in mind the problems Boeing’s Dreamliner and Samsung’s Galaxy 7 phone have had with battery fires. They use the same technology.

  5. I would not park a Li-ion battery car in my garage or close to my wooden home. Nor would I install a Li-ion storage battery in my house. Too many reports of fires. Battery storage of energy has not, yet, been figured out.

  6. @An Engineer (software?) – of course it matters whether it was a conversion, or designed from the beginning to be safe and electric. Battery compartments need to be designed to prevent punctures, something you get in a car designed to be electric from the ground up. As Samsung can attest, the quality of the actual battery matters as well. And of course, the proper statistic is fires per mile driven, not per vehicle.

  7. “@An Engineer (software?)”

    Electrical. Yourself?

    ” – of course it matters whether it was a conversion, or designed from the beginning to be safe and electric.”

    Conversions are not inherently unsafe, and factory iron is not always safe. Well-designed conversions are as safe as stock, and can be better.

    “And of course, the proper statistic is fires per mile driven, not per vehicle.”

    True for collision events, but not for electrical mishaps, which can happen while the vehicle is and has been quiescent.

  8. I didn’t say conversions were inherently unsafe, I dispute your claim that it is “beside the point.” A per mIle stat is more useful than total vehicles because of the limited range of electric cars. A per vehicle measure will undervalue the risk for electric cars. Both gas and electric cars are subject to fire risk when off, so not sure it matters, unless you want to lump in defective home wiring fires.

  9. “I didn’t say conversions were inherently unsafe,”

    Read your text: “of course it matters whether it was a conversion, or designed from the beginning to be safe and electric” again.

    “Both gas and electric cars are subject to fire risk when off, so not sure it matters,”

    I explicitly referred to electrical mishaps. A charged battery contains energy that can be released in an unintended manner whether the vehicle is making miles or not. Distance traveled is therefore not the key parameter in this comparison.

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