The bottom line is, Chevy Volts and all the other vehicles that use lithium-ion batteries are safe, because they've been engineered to handle the problems that are inherent in those chemistries.
That's not to say that anomalies won't occur. But even for the most skeptical of us, it's got to be hard to believe that all of the engineers at GM, Ford, Nissan, Mitsubishi, Tesla, Toyota, BMW, and every other maker of electric cars and hybrids could have badly miscalculated the risks. No, the fact is, they knew the risks going in, and they've engineered for them.
The cooling system in the Chevy Volt's battery was designed to handle the potential temperature instabilities of lithium-ion batteries. (Photo courtesy of GM.)
In truth, the real downside of those risks is the cost that's required to manage them. That's why so many industry experts quote high prices when they talk about EV battery costs. Automakers don't just slap blocks of cells in hollowed-out car trunks. They invest heavily in designing and building cooling systems. Then they lay out more money to cover warranties, failures, and liabilities. If the Volt fires tell us anything, it's that carmakers have good reason for doing so.
Sadoway of MIT believes that cost, not safety, could be lithium-ion's Achilles heel. "Cooling systems can be built for this application, but cost is an issue," he writes. "In my judgment, the long term solution is to replace the electrolyte with something that is less capable of being rendered unstable."
In the two weeks since the Volt story came to light, news sites have had a field day. Time Magazine asked, "Are electric cars safe?" The New York Times called it a "setback for electric cars." And scores of bloggers opined that it was "only a matter of time" and that GM's response was "troubling."
But if we're worried about the safety of electric cars, we shouldn't be. Consider this: Every day, most of us sit in vehicles that burn gasoline. The gas runs through fuel lines beneath us and around us to an engine, where it explodes repeatedly.
>"If that was a gasoline car that was not properly constructed, and the gasoline burst into flames, it would have been a far worse accident, because of the big difference in energy," Cairns says. "Yet, we accept the tank of gas, and the energy that it represents, and the type of fire that it represents, every day."
Yes, we accept the tank of gas because we trust the engineers to beat the risks. And the situation should be no different in the case of the Volt.
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 think at this point we clearly don't know the complete range of risks in the Volt. Nor, re the earlier comment, do we know exactly how many Volts have been sold. We'll be keeping up with both issues in our continuing coverage on Design News; thanks for the comments and for bringing these issues to the fore.
Rod, according to Hollywood, your Pinto experience is not typical. If you do a survey of all car crashes in films or on TV, all car crashes result in fire & an explosion. This is specially true if you are a bad guy.
Remember, when GM first tested airbags, the prototypes kept decapitating the dummies.
The danger of any exotic chemical batteries and energy cells is well known. The Bolder TMF cell can do a similar job powering hybrids...Remember the Chrysler EXS created some time ago? Bolder uses a LEAD ACID combination with plastic shielding isolating EVERY CELL in the pack. That cell system was used in the ESX. No fires, no leakage except from the damaged cells in a collision...The amount of standard car battery electrolyte is contained in the matrix. No more than a few drops per cel actually leaks out.
Contrast that to the problems the ( re) VOLT (ing) has.
Used regular materials in power pack construction and the problem goes away.
Too bad the company got outsourced to the pacific rim....
I heard that of 4 Chevrolet Volts involved in crash testing, 3 ended up burning down. 75% suffered total destruction. Of course I'm not sure I believe that, if Chevrolet conducted the crash tests and got those kinds of results then I'm sure they wouldn't have released the car for production.
anytime you sit in a vehicle that has enough stored enegery to propel a 4000+ pound object some 300 miles you are taking a risk.
Fortunately gasoline is a fairly safe fuel - its hard to ignite in bulk liquid form, msotly the vapors are extremely volatile.
The lithium is also hazardous, shorts created by physical shocks in abnormal conditions like collisions risk igniting the batteries. Apparently damage to the cooling system can also cause delayed fires - this is particularly worrisome because circulation cooling systems are active whereas all the gas tank protection is primarily passive in nature.
I guess we'll know a little farther down the road.
Manwhile, is it true that GM has only sold 6-10,000 of the very hyped Volts? Are they on track saleswise?
I'd also like to add that many automotive fires have been caused by far lower energy density storage devices, namely the lead acid battery! While the battery itself may have had few ignition issues the vehicle wiring has had plenty. A short in a starter motor solenoid can result in an overheating starter motor and/or its power cable. Fusable links in many instances have not opened on time. With the trend to thinner and thinner wiring to reduce vehicle weight and the talk about raising the bus voltage to 24 or 48 volts to further reduce losses, the peak fault currents will rise even for non electric drive vehicles.
Regardless of the energy source, the density and amount of "fuel" required to power a practical vehicle will always be dangerous. However, it is kinetic energy that poses the biggest threat to a vehicle's inhabitants.
I understand your question. Is there a significant risk to the consumer, like there was with the Pinto? Others appear to have missed the point. It is interesting that there have already been 3 fires, with so few sold. However, the question should not be asked if there is an issue with the Chevy Volt Lithium-Ion batteries but if there is an issue with all electric/hybrid cars with large battery systems. Lithium-ion batteries were not stable enough to be used in consumer products until very recently. Before this, they we would explode above 70 degrees F. Consumers tend to think batteries are benign things - safe. They are energy storage devices and if mistreated can hurt people. They do catch fire and when they do, they burn hot. They also explode and they tend to explode in a cascading fashion.
To me for Chevy to be willing to buy back the vehicles from worried purchasers means that GM is starting to pay attention to customer reaction; after all GM has a reputation of putting vehicles on the road and letting the customer find the bugs for them.
I don't disagree with all you state, I agree that if done appropriately, electrics will always be safer than a compairable gasoline car. Ultimately, any basic safety analysis would start with a comparison of energy density and volitility, both of which are higher with gasoline right now and probably will continue to be for the next 10 years... though batteries are improving.
Yes, my states aren't 100% comparable, you'd have to reduce everything and make it a per capita comparison. But still, one can look at this data and make a general order of magnitude comparison to draw the conclusions I did. If you disagree with the conclusions, then do the hard math and challenge them.... but I suspect your just challenging my methods and not my conclusions in which case I agree and attribute the problem to laziness.
I do disagree with the claim of "catostrophic failure" of lithum batteries when they fail. Again, an honest attempt at quick comparison, worst case senarios only: When a lithum battery falses, we end up with a short which could catch fire assuming the cooling system fails. When a gasoline tank fails, say in the case of the pino, gas leaks onto a hot surface, igntites, and could potentially ignitude the gas tank (it does happen though rarely) and you get an explosion. An explosion is obviously more dangerous than a fire in most circumstances. I could honestly say that a gasoline powered car could, theoreticaly, be more safer than an electric, but it would require greater isolation than their lithium battery counterparts due to energy density. They could cordin off the gas tank into isolated sections, but to pass the safety rating of electrics, it would have to contain more isolation. Generally, lithum batterys do not fail "catastrophically"... I mean, can you name one catastrophy that has resulted from a lithum battery failure? It all goes back to energy density.
Basically it was a design flaw that left the car more susceptible to fire in a rear-end collision. I was read-ended while driving a Pinto. The car was totaled, but no fire.
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