What was claimed
“The problem with crashing any EV is that If you are trapped, you’re dead, as it is impossible to remove victims” because the high-voltage battery cannot be safely shut down.
False: Emergency shut-off systems in EVs are designed to disable high-voltage batteries in serious collisions, making it safe to cut into the vehicle to rescue occupants. First responders can also disable the high-voltage batteries by disconnecting the car’s standard 12-volt battery.
By Raymond Gill
As electric vehicles become increasingly popular, concern about their safety is being discussed on social media, with users spreading misinformation about their high-voltage batteries.
One such post on Facebook, which has been shared almost 10,000 times, claims that EV car crash victims are likely to die because first responders must disable the high-voltage battery before rescuing the occupants.
The claim that “the problem with crashing any EV is that If you are trapped, you’re dead, as it is impossible to remove victims” is incorrect.
The post, which was created by an Australian account, was based on an unsourced anecdote from New Zealand.
In the anecdote, the poster claims that if people are trapped inside a Nissan Leaf, the fire brigade must isolate the high-voltage battery beneath the car seats before they can cut into the car.
“In the leaf, the isolation plug is under a bolted cover on the floor between the front and back seats,” the post says.
“Once the cover [of the isolation plug] is removed, the 3 pairs of gloves required by law are to be fitted, cotton, rubber, and leather. Then with hands resembling lamb roasts they can try and disconnect the 3 stage electrical. Then they can cut into the car,” the post says.
Not so, according to EV FireSafe, an Australian research project funded by the Department of Defence to research and advise on electric vehicle battery fires and emergency responses.
EV Firesafe’s project director Emma Sutcliffe, who is also a volunteer firefighter, told RMIT FactLab that all EV passenger vehicles have a low 12-voltage battery (like any internal combustion engine-powered car) as well as a high-voltage battery.
The low-voltage battery provides power to electrical systems controlling its lights, windows and radio, and the high-voltage battery gives the EV its traction.
She said in the event of an accident involving an EV, “disconnecting the low-voltage battery disables the high-voltage battery”.
And in the case of a collision in which its airbags are deployed, an EV will automatically isolate the high-voltage battery on impact, she said.
EV FireSafe has developed a set of EV guidelines called “extrication considerations” in collaboration with road rescue agencies, EV manufacturers and international defence and civilian emergency agencies. It was presented last month at the Australasian Road Rescue Organisation conference in Tamworth.
“When emergency responders attend an EV incident, they should first locate the low-voltage battery that is usually found under the bonnet of the car, as it is in any internal combustion engine-powered car,” Ms Sutcliffe said.
“First responders can then remove its negative terminal, effectively isolating the high-voltage battery. The Nissan Leaf HV battery can be isolated by disconnecting the 12-volt battery in this way,” she said.
The Nissan 2021 guide advises first responders to Leaf incidents to disconnect its 12-volt battery or remove the 12-volt fuses under the bonnet, either of which will disable the high-voltage battery.
Emergency services organisations, such as Victoria State Emergency Service, also produce their own road crash guides with similar information.
Ms Sutcliffe said the mantra for anyone approaching an EV in any incident should be “identify, immobilise and isolate”.
EVs can be identified by first responders as these cars carry a mandatory blue EV badge on their number plate in Victoria, NSW, South Australia and Queensland, a rule that is expected to be applied nationally, she said.
All emergency response guides provide instructions on how to disconnect a high-voltage battery if it is ruptured, she said.
“In some vehicles, like all Tesla models, it’s an orange cut loop located under a cowling under the bonnet and marked with an orange tag with a firefighting helmet icon. This should be cut in two places to avoid accidental reconnection. Other EVs, like the Hyundai Ioniq 5 have a pull fuse,” she said.
And as for wearing three pairs of gloves “by law” to avoid hands burning, the poster is wrong again.
“There are no laws stating that responders should wear three pairs of gloves,” Ms Sutcliffe said, but added that each emergency organisation or EV manufacturer will have guidelines as to the appropriate protection it recommends when disconnecting the high-voltage battery.
She said there had been fewer than 400 battery fires recorded globally since 2010 from a stock of more than 16 million EVs. This information is based on EV FireSafe’s own database of passenger EV battery fires globally since 2010, which has found 261 verified incidents and another 61 incidents under investigation.
EV Firesafe’s database is not public as yet, but a searchable open database is expected to be available later this year.
“Our research found a very low risk of electrocution and we have not found any cases or near misses for responders or EV drivers,” Ms Sutcliffe said.
False. It is incorrect to say that the only way to safely rescue people trapped in an EV after an accident is by directly accessing and disabling its high-voltage battery. Disconnecting the car’s standard 12-voltage battery, which is usually located under the bonnet, will disable the high-voltage battery – if it hasn’t already been automatically disabled by the deployment of airbags in a collision. Occupants trapped in EVs after an accident can be safely rescued.
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RMIT University acknowledges the people of the Woi wurrung and Boon wurrung language groups of the eastern Kulin Nation on whose unceded lands we conduct the business of the University. RMIT University respectfully acknowledges their Ancestors and Elders, past and present. RMIT also acknowledges the Traditional Custodians and their Ancestors of the lands and waters across Australia where we conduct our business - Artwork 'Luwaytini' by Mark Cleaver, Palawa.