The Chevy Volt cross-country Drive for Innovation is rolling south toward our next stop in Raleigh, N.C., and we've been catching up on news surrounding the Volt, its lithium ion (LiOn) battery, and charging stations -- specifically, whether the Volt is a fire hazard.
Some sites have seized on the news to push LiOn technology as a killer in the wings; others offered a tempered view, suggesting that, at least for now, it's a tempest in a teapot.
Chevy Volt in a side crash test, performed by the Insurance Institute for Highway Safety.
To recap, we know of three fires in which Chevy Volts were involved or nearby:
A fire destroyed a garage in northwestern Connecticut. The owner -- a volunteer firefighter named Storm -- had a Volt and a home-converted Suzuku Samurai EV. Here's a link to his blog on the fire, where he writes that the cause was "definitely not the Volt." (Here's a link to local TV coverage.) No cause has been determined.
In Mooresville, N.C., a fire in a three-car garage that housed a Volt spread to and destroyed a luxury home. Initial suggestions identified the 240V charging station as the possible cause. That's since been rejected, as fire officials have said the blaze started away from the vehicles and charging station. But no cause has been determined.
The National Highway Transportation Safety Board crash-tested a Volt, pushing it into a pole at 20 miles an hour. The car performed well and was stored outside in the cold. Weeks later, the car caught fire. The fire apparently was caused by a short when the punctured coolant system leaked into the LiOn cells.
The LiOn challenge
We've known about LiOn benefits and hazards since the technology's introduction. Studies and observations have been unceasing. Last decade, the FAA looked into the matter after shipments of LiOn batteries caught fire aboard or near two planes.
Small fire sources can cause big problems, as LiOn cells quickly fuse together and propagate the fire. Some traditional suppressants like Halon 1301 bromotrifluoromethane) might be ineffective; water is increasingly seen as the most effective way to put out such fires, according to a report published this spring by the Fire Protection Research Council.
Last year, a cargo plane caught fire and crashed in Dubai, carrying goods that included LiOn batteries. No cause has been identified.
Given the billions of LiOn batteries in the world, one could argue that failure incidents are marginal (how many lead-acid battery failures go unreported?).
But it's not a subject to be taken lightly. GM certainly isn't. It reported last week that it's been sending SWAT-like teams to crash events to de-energize the batteries. GM EV global chief engineer Jim Federico stands by the company's EV innovation.
Given what you know, how would you design a LiOn-powered EV to be safer? Or is it safe enough?
Story courtesy of Drive For Innovation. Design News will have additional coverage of the Volt battery issue upcoming.
For further reading
To keep up with our Chevy Volt coverage, go to Drive for Innovation and follow the cross-country journey of EE Life editorial director Brian Fuller. On his trip, sponsored by Avnet Express, Fuller is driving a Volt across America to interview engineers.
I have to agree with TIm that this is more likely a case of fear being raised over a relatively new and unknown technology rather than a some sort of sustainable threat. Yet it does give me cause for concern and make me wonder about additional design considerations that could help protect against the fire threat, however small. There is actually some precedent--several years back, I remember an Apple recall on littium ion battieries used in its laptops because there were reports of them catching fire. I'm wondering if there are parallels?
It was 1997 and I had just seen my very first Lithium cell pack for a cell phone.I was the Accessories Products Development Engineering Manager for the Motorola iDEN phones.We had recently migrated from the long-standing NiCd batteries to Nickel Metal Hydride (NmH) technology as a green initiative to eliminate Cadmium, but that initiative was short-lived as Lithium promised higher capacities and greater number of charge/discharge cycles, although costing a bit more than the NiCd or the NmH.500 million cell packs later, the only fires or faults we had documented were due to non-standard charging equipment; usually from a Chinese 3rd party knock-off charger that didn’t include the proper thermistors or relevant safety circuitry.Its like Nuclear Power.Follow the rules established and it will serve dutifully. I hate to see Li-Ion get a bad rap.
One can imagine the hysteria if hydrogen becomes a viable fuel for domestic use. Dual dangers of flammability and extreme cold would cause headlines like "Freeze and Burn at the Same Time!"
There's always been far too much hype around electric vehicles and lithium-ion batteries, and the recent Volt fires are no exception to that. Yes, the electrolyte in lithium batteries is a highly flammable liquid but, as Brian points out, there's nothing new about that. We've known about it for a long time. The truth is, we really don't have any reliable details on the cause of these fires, but we can definitely say this: If an improperly-constructed gasoline-burning car had burst into flames, it would have been a far worse accident, and it would have happened a lot faster than three weeks.
I really do not know if the LiON batteries catch fire. I find it hard to imagine that Volts randomly burst into flames, but I can guarantee that gasoline which is the alternative to batteries is higly flammable, A spark while fueling has a real chance of igniting vapors of gasoline. However, it is still common to see people smoking while filling up at the local 7-Eleven. This seems to be a case of fear of new technology showing fears that may or may not be warranted.
Like gasoline, Batteries hold a lot of energy so if damaged, could short and cause a fire. But how many Fords cause so many fires from ignition switches!!
And each car already has batteries and fires from them haven't been much of a problem. But dying in gasoline fires, yes a real problem. EV's ones, not so much.
And it's the electric power causing the fires mostly, not the batteries bursting into flames.
And few Lithium batts use flameable electrolyte anymore. Most can be shot with bullets without causing problems so all in all, EV fires are rare and likely to stay that way.
There's always an aspect to these stories where they take on a life of their own, regardless of what the facts turn out to be. A case in point is the Toyota unintended acceleration of a few years ago. The more distance one gets from that, the more it looks like driver error was the cause in a lot of so-called instances. Not saying that's the case here, but I am saying, as Brian notes, we need to wait for a full investigation before jumping to conclusions. For example, if you looked at 100 percent of charging systems for everything, you'd find some fires.
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