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Discussion in 'Battery Discussion' started by vfx, Jun 10, 2011.
Fed launching $8.75M study into fire risks from EV batteries Autoblog
Good; vindication of the safety of Li-ION over gasoline... by 2014. Let's watch as armchair pundits come out and spend the next two years speculating on just how dangerous EVs are.
Data from here shows that in the late 90s there were about 280,000 passenger vehicle fires per year.
There are about 130 million cars and 110 million trucks in the US. I am not sure how many of the trucks are passenger vehicles.
That means about 1 in 900 ICE vehicles has a fire each year.
That gasoline is dangerous stuff.
Yes, interesting. Where's the "Fed launching $8.75M study into fire risks from gasoline - Autoblognik"
Can anyone say conspiracy? Has there actually been an electric car fire reported?
Cute video, but "4 million of us run out of gasoline every day"? I've never run out of gas nor do I ever remember talking to someone who has ever mentioned running out. Granted, it happens, but 4 million a day sounds preposterously high.
I've actually done it twice. :redface: I'm talking quite a few years ago. Once I was just stupid, the other time I had a faulty fuel gauge. I've taken to using the trip odometer instead of the fuel gauge; much more reliable.
I did once in undergrad, driving a borrowed car with a nonfunctional fuel gauge.
But lets try to stay on topic which is fires.
Honestly, yes. I've even seen one in person (a couple years ago at Laguna Seca).
In recent memory there was Niel Young's LincVolt which went up in a warehouse in nearby San Carlos (taking $1M in memorabilia with it), a "professionally" converted Nissan SUV that caught fire on a ferry in Europe destroying the surrounding cars and putting the company out of business, and a homebrew EV in Connecticut that also destroyed the owner's new Chevy Volt parked next to it.
The common thread is these are all conversions. Some of those fires were likely due to cheap Chinese cells and/or an inadequate BMS. I've never heard of a fire from an OEM EV. Certainly Tesla, Nissan, and GM have taken a lot of care in the design and safety of their battery packs.
I know of two more in the UK, again both related to conversions.
I've personally seen two ICE cars burn. Man do they ever go up! I'll bet the rate of car fires for OEM vehicles will be a tiny fraction compared to ICE cars. One wonders why they are even studying this...
Because it's always good to know the answer rather than think you know, particularly from a liability viewpoint. Sometimes you get surprised or find out something tangential that turns out useful.
Fault Found in Battery Pack of Flaming China Taxi | PluginCars.com
cheap Chinese cells and/or an inadequate BMS...
"in order to push the limits, sometimes you have to EXCEED the limits"
-- B. Varsha, F1 commentator, Australian GP, 2xxx
One aspect of battery packs for EV use, is the long-term effects of shock/vibration:
batteries + packaging
You see bolts, littering roads, loosened up due to high-frequency vibration. Have there been any long-term Validation tests performed for battery-packs? Probably not!
You will recall the issues the Tesla Roadster had with multi-speed gear boxes (had never been done before)..they failed under Reliability/Validation tests. That 2006 MSNBC video where M. Eberhard took the reporter on a test-ride, where the Roadster pulled over due to a tranny problem. Multiple vendors weren't able to solve the problem. This contributed to the delays & cost over-runs, & EM unfairly blaming Martin & company (incl Wally Rippel, Caltech alumni, former ACP engineer).
Martin (legitimate Elec Eng degrees from UIUC, my former office-mate in grad-school) had advocated a single-speed, who had the engineering sense to use a conservative approach:
"Discretion is better part of valor"
It was EM (whose physics degree was challenge by the lawsuit, & even the Stanford grad-school story is suspect), who went with a risky
"all or nothing"
approach: electric door handles, re-design of chassis (inconvenient for his wife)
You can see EM take bigger & bigger risks (recent SpaceX development), which will eventually catch up with him.
I will quote R. Feynman (who taught W. Rippel, see Tesla's blog post "Feynman..a curious character"):
Space Shuttle Challenger disaster - Wikipedia, the free encyclopedia
That Model S battery pack slung underneath the chassis is ANOTHER unproven concept, without long-term Reliability/Durability tests. Car chassis flex/twist, will also get HIT (high-centered, etc). The packaging better be robust, otherwise there could be a potential short-circuit, fire. A few bad accidents plus fire..major PR disaster. Recall the infamous Ford Pinto in 70's, fire hazard when rear-ended.
Forget the theoretical risk of fire in EV's--
How about today's NY Times, about the fire danger in "millions of Jeep Cherokees"
Crash Tests Suggest Jeep Fire Risk, Safety Group Says - NYTimes.com
That Same NFPA also quotes that there are 33 reported fires an hour. More than one every two minutes. For me, that's easier to understand. And with the Model S batteries being water cooled, it will be hard to have your "incident of self immolation" at all.
Report: Electric bus catches fire in Shanghai Autoblog Green
Fortunately no one was injured. Contrast that with this diesel bus fire mentioned in the comments:
Channel 6 News -- Bus fire kills 41 passengers in central China
This time suspicions seems to be on the EVSE.
Chevy Volt possibly involved in second garage fire, this time in North Carolina
Warning issued for electric car owners after Mooresville house fire - News Story - WSOC Charlotte
I'll have to ask the people at Duke about this. We are working on a smart grid project with them.