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.
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.
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.
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.
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?
Am I correct in making the inference from the story and from JimT's comment that heat is the causative factor? If so, then safety is in play during driving (a well-designed battery cooling system) and can be brought into play during charging (if the rules JimT mentions are followed). So the outlier is in crashes. What can be done here? Would seem like there needs to be more protection surrounding the batteries, which means more weight, which means poorer performance (which then means you need more batteries). Similarly, poor fire protection in crashes might indicate the need for an active fire suppression system, which would also add weight, cost, etc...
Three fires where Chevy volt vehicles were in the area, only one of them remotely attributed to the car, and that one was a crashed vehicle improperly stored? Does this really mean anything other than a slow-news week? Of course any vehicle that has crashed may catch fire. In most cars the battery is close to the front, both for cooling and for weight distribution. And one of the first things that a responsible responder will do is to disconnect the battery. So we know that any battery in a crash does indeed constitute a hazard. But most vehicles are never crashed, so that does not apply to them. The design of vehicles using battery power, at least those made by the aouto companies, has been one of extereme caution. All of the car companies are aware of the hordes of hungry lawyers waiting for some mistake, with the result that they have multiple layers of safety provisions in the design of these vehicles.
The external charging systems are another story, since some of them are not made by the automakers. But standard good engineering practice, in addition to the various electrical codes, plus the need for certification, assure that these systems are not fire hazards. Consider what a proven fault would do to future sales, and it is clear that the motivation to be safe is quite strong.
That leaves the installation of the charging system in the home as a potential source of a hazard. BUt then consider that most of those installations would be inspected by a municiple building inspector, and it is clear that any chance of an incorrect installation is unlikely. What remains are do-it-yourself installations by homeowners, who have unknown skill levels. That would certainly be brought out in any fire investigation, and loudly proclaimed as the cause, at least by most media. But we have not heard of any such installations being related to any of the fires.
So the logical conclusion based on current information is that non-crashed vehicles are not any greater hazard than any other ones. Now, do we hear any complaints about the hazards related to gasoline powered vehicles? Gas vapors from an open fill tube are far more likely than electrical leakage from an open battery charging door.
This is incredibly silly, use a little common sense. Batteries are inherently safer than a 14 gallon can of gasoline. All the examples they give are false examples anyway. They give 3 examples, 2 of which are disproved in the same sentence that identifies them. The last one was a car that survived a head on collision, and then was inappropriately driven without inspection and repair.. i.e., this article is nothing more the perpetuation of the kingdom of fear with the goal of maintaining a society who's economy is based on an obsolete energy source, fossil fuels. If you were really concerned about driver safety, and not prematurely ending any and every technology that can compeat with fossil fuels, you would have performed a comprehensive comparison of which is more dangerious, gasoline or batteries, based on likeliness of fire and severity of fire. Without question, and I do dare to request a challenge, without question, an electric powered engine + fuel containment system will always, always without question, be safe than an equivalent gasoline powered engine + fuel containment system. For example, if you were to intentionally sabotage both types of cars with the intent of inflicting the most damage, the best you could do with the electric car is start a fire and engulf the car; With a gasoline car, you could cause a massive explosion + fire. Of note, the Volt is both gas and electric, lol, so you got the worst of both worlds. Chevy = Big Oil, still refusing to give up the obsolete fuel source... killing millions every year... for nothing more than immediate profit at the cost of long term profitability and technological progress.
The landscape of product development is changing. Electronic components and the devices that use them are shrinking, while power and functionality are rising. As a result, heat management is now in the forefront of the design process.
Ahead of their appearance at Design & Manufacturing Minneapolis, we look at some of the engineering behind two robots from the hit show, BattleBots, as well as some tried-and-true fighting tactics engineers should keep in mind when taking their own robots into battle.
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