Breaking News
News & Analysis

Tesla Battery Fire: Musk Responds & an Expert Explains

10/7/2013 01:55 PM EDT
26 comments
NO RATINGS
More Related Links
View Comments: Threaded | Newest First | Oldest First
krisi
User Rank
CEO
really?
krisi   10/7/2013 2:12:46 PM
NO RATINGS
"The chances of running over something that actually punctures the underbelly of a car are small." ???

Caleb Kraft
User Rank
Blogger
Re: really?
Caleb Kraft   10/7/2013 2:17:23 PM
NO RATINGS
While I'm sure he was speculating, do you suspect that the undercarriages of cars are punctured frequently?

krisi
User Rank
CEO
Re: really?
krisi   10/7/2013 2:30:56 PM
NO RATINGS
I am en engineer...I like the data...I don't like "small"..."small" compared to what?

Caleb Kraft
User Rank
Blogger
Re: really?
Caleb Kraft   10/7/2013 2:43:54 PM
NO RATINGS
Yes, ofcourse. I wonder where someone would even look to find that kind of data. Surely the auto industry has a recommended thickness or impact resistance for the bottoms of vehicles based off of some kind of data.

Sheetal.Pandey
User Rank
Manager
Re: really?
Sheetal.Pandey   10/7/2013 3:29:47 PM
NO RATINGS
Great to know that control system informed the driver to move out. That's proactive. That also proves safety is first.

Max The Magnificent
User Rank
Blogger
Re: really?
Max The Magnificent   10/7/2013 3:50:29 PM
NO RATINGS
@krisi: I don't like "small"..."small" compared to what?

Compared to somethoing that was bigger LOL

krisi
User Rank
CEO
Re: really?
krisi   10/7/2013 3:52:47 PM
NO RATINGS
LOL Max

PocketBrain
User Rank
Rookie
how 'bout the batteries
PocketBrain   10/7/2013 4:07:45 PM
NO RATINGS
I wonder what is the barrier against using a safer battery type.  Cost?  Energy density?  Search the youtubes for nail-puncture videos of standard Lithium Ion cells and A123 Systems' batteries and you'll have a good comparison..

polylith
User Rank
Rookie
Re: how 'bout the batteries
polylith   10/7/2013 4:18:08 PM
NO RATINGS
If you take the statements are face value, that Tesla battery fires are 5 times less likely and have 1% the combustion energy of gasoline fires, isn't the car's battery safe enough as is?

Bert22306
User Rank
CEO
Regular cars also catch on fire, from time to time
Bert22306   10/7/2013 4:47:02 PM
NO RATINGS
Hasn't anyone ever seen a vehicle fire?

Lithium batteries sure are getting a bad rap, of late. PCs, airplanes, cars, anything more? I'd like to know what kind of debris this Tesla ran over, specifically, and then compare what it might have done to a gasoline tank. Too much vague generality tends to make me skeptical.

Anyway, to continue my mantra, battery powered EVs seem unimaginative and apologetic, at best. It's time to get better EVs out there.

GMF
User Rank
Apprentice
Musk's claim is baseless
GMF   10/7/2013 4:56:09 PM
Musk claimed "...Had a conventional gasoline car encountered the same object on the highway, the result could have been far worse."

Should not be too hard for Musk to find out how many car fires caused by bottom impaction.
The fact is a conventional gasoline car has much less chance to catch fire in the same situation as Tesla, although the fire could be much worse in case it did start. First, a gas tank in a car is far away from ground, comparing to Tesla's bottom mounted battery pack. Secondary, the bottom area of gas tank is much smaller than Tesla's battery pack.



Caleb Kraft
User Rank
Blogger
Re: Musk's claim is baseless
Caleb Kraft   10/7/2013 4:58:29 PM
NO RATINGS
Many cars now(late 90s onward) mount the gas along the bottom of the car (my minivan is a good example). 

 

I think he was speculating about the fact that the tesla has additional armor and batteries to protect the passengers. That debris could have theoretically entered the cabin of a normal car. 

GMF
User Rank
Apprentice
Re: Musk's claim is baseless
GMF   10/7/2013 7:24:07 PM
NO RATINGS
 

Re: Musk's claim is baseless
Caleb, You're right. I did some search about fuel tank safety regulations. Only thing I found is FMCSA393.67 which didn't prohbit bottom mount, not even for gastank mounted after real axle. Only impact related test is 30 feet drop test. Maybe the time to adding bottom impact test for gasoline cars and EV/HEV.

http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?reg=393.67
http://www.autosafetyexpert.com/defect_fueltank.php?pagetitle=FUEL%20TANK%20-%20FIRE

daleste
User Rank
CEO
Re: Musk's claim is baseless
daleste   10/7/2013 11:18:24 PM
NO RATINGS
It is an impressive fire, but I have seen gasoline cars burn like that too.  The numbers do indicate fires happening more often in gasoline vehicles, but I don't think they have enough data yet to prove that batteries are safer for fire danger.

rick merritt
User Rank
Author
Re: Musk's claim is baseless
rick merritt   10/8/2013 12:44:02 AM
NO RATINGS
@Caleb: Great reporting!

I assume the video of the burning Tesla was AFTER the fire department puctured the firewall. Is that right?

Agreed that the realtive saftey of the Tesla is very high and should not spawn a frenzy of EV fears. That said, this is a marketing nightmare and could undermine the company and set back the EV market.

A viral video of a flaming car is so much more powerful than 300 words explaining the technical reality of what happened and the relative saftey of EVs and gasoline engine cars.

Caleb Kraft
User Rank
Blogger
Re: Musk's claim is baseless
Caleb Kraft   10/8/2013 5:19:30 PM
NO RATINGS
Yes, this video is after the fire department punctured the firewalls allowing the fire to vent upwards.

Caleb Kraft
User Rank
Blogger
Re: Musk's claim is baseless
Caleb Kraft   10/8/2013 5:20:14 PM
NO RATINGS
I've seen plenty of vehicle fires. Heck, youtube is full of them. I think this is wildly blown out of proportion myself.

Frank Eory
User Rank
CEO
Re: Musk's claim is baseless
Frank Eory   10/7/2013 6:32:53 PM
NO RATINGS
The undercarriage has armor plating, there are firewalls between battery modules and between the undercarriage and the passenger compartment, and still a foreign object impaled one or more of the batteries, causing a fire. Even without hard data to compare to gasoline combustion engine vehicle fires, that certainly sounds like an outlier incident to me. It is also important to note that the driver was warned to exit the vehicle and escaped uninjured. You don't get that advance warning with a punctured gasoline tank.

Caleb Kraft
User Rank
Blogger
Re: Musk's claim is baseless
Caleb Kraft   10/8/2013 5:21:01 PM
NO RATINGS
I know, the warning system is pretty incredible. I wish I would have had that for a few mechanical failures I've seen!

Sanjib.A
User Rank
CEO
Re: Musk's claim is baseless
Sanjib.A   10/21/2013 11:39:06 PM
NO RATINGS
How did the warning system work in Tesla? Did it detect the mechanical failure of the armor and infringement into the battery? Or did it detect a "battery over-heating" scenario after the punch was made and detect a possible fire (which I am guessing)? If the warning system is designed to detect infringement of the battery armor, this is incredible. 

p_g
User Rank
Rookie
Re: Musk's claim is baseless
p_g   10/9/2013 1:17:23 PM
NO RATINGS
But gasoline catching fire is far more propable than battery catching fire. There is not much inflamable material in the Tesla (compared to gasoline).

DrQuine
User Rank
CEO
Viral video vs. Scientific Explanation
DrQuine   10/8/2013 9:39:06 PM
NO RATINGS
When a video goes viral, a sample size of one takes on an extraordinary weight in the public eye. Scientific explanations (regardless of how accurate) have a tough time competing with an iconic image that is seared into the mind. That said, it was very interesting to read the "rest of the story".

rick merritt
User Rank
Author
Re: Viral video vs. Scientific Explanation
rick merritt   10/9/2013 2:16:17 AM
NO RATINGS
@DrQuione: Agreed!

boblespam
User Rank
CEO
Statistics ?
boblespam   10/9/2013 8:45:52 AM
NO RATINGS
I love when engineers come to conclusion from statistics based one one event !

OKays probably Musk isn't an engineer, but some others here have no excuse ;-)

"Musk explained that combustion engines currently experience fires at a rate of one fire per 20 million miles driven. In contrast, Tesla has shown one fire per 100 million miles driven"

JCreasey
User Rank
Freelancer
Re: Statistics ?
JCreasey   10/9/2013 2:49:55 PM
NO RATINGS
The number of fires per mile is not the statistic I think you need to consider. The number of petrol tank penetrations to battery penetrations is what you want to compare.

I'll bet there are many more petrol tank penetrations where gasoline is spilled and there is no fire. Unfortunately where a battery is concerned, most penetrations (where the physical cell is compromised) are likely to self ignite. That is why they had to put the extreme reinforcing on the base and between cells as firewalls. 

For EV batteries you need to consider

1.     There is a self ignition capability (chemistry or physical pack faults)

2.     There is an immediate fire capability if the chemistry/construction is compromised

Tesla, if successful will produce millions of batteries to build into their EV packs, and just like laptop batteries they will have a failure rate above zero. Unfortunately, any failure may result in very large uncontrolled energy discharges almost guaranteed to have an associated fire (or as in the Boeing experience, heat destruction and smoke).

While gasoline tanks are an obvious potential fire hazard, it is not a given that every fault will result in fire. IMHO Hydrogen (metal hydride) storage is probably safer than either gasoline or any of the battery chemistries.

NewStandard
User Rank
Rookie
Typo
NewStandard   10/10/2013 10:23:29 AM
NO RATINGS
The last two paragraphs of this post are missing a quotation mark. It's not clear whether the author or Dr. Sadoway offered the opinion that EVs need to cost under $20k.  Whoever did, that's an oddly high bar to meet when you consider the drastically reduced operational costs of EVs--fuel less than half the cost of that for a Prius and almost no maintenance required at all. Moreover EVs are smoother and quieter than any ICE on the road at any price, at least as self-generated (immunity to outside noises and suspension being independent of drivetrain). The market has already placed a high cost premium on those qualities. People just need to learn that and need to feel comfortable with adapting to something different. Human nature is against doing that.

In my opinion the technology obstacle is that battery development needs to be improved to allow an honest 200 miles of range with very little degradation over 200k miles or so. It may take a solid state battery or something else more stable. If the masses cannot feel comfortable paying the price of having to recharge overnight after "only" 200 miles in order to rid themselves of the drawbacks of fossil fuels, then our addiction to oil may indeed be fatal to humanity.

Flash Poll
Radio
LATEST ARCHIVED BROADCAST
EE Times editor Junko Yoshida grills two executives --Rick Walker, senior product marketing manager for IoT and home automation for CSR, and Jim Reich, CTO and co-founder at Palatehome.
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Times on Twitter
EE Times Twitter Feed
Top Comments of the Week