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Crashing an electric car

Hi!

I was wondering if any crash tests has been done with tesla cars. I'm a bit worried the consequences of the car battery blowing up/taking fire, the fumes it might produce or battery acid leaks.

Also the structure of the car in respect to protective beams, and the lack of a motor in the front compartment diverting energies from a crash in normal combustion cars.

From what I've heard and read about, along with taking apart some of the Li ion batteries along with my understanding of the way the Teslas are built:
1. There is no acid in Li ion batteries
2. The large car battery is very protected in terms of layers of plastic
3. There is a coolant being circulated to keep the batteries at a specific temperature
4. The materials in the Li ion rechargeable batteries are basically benign compared to other fuels (look up the MSDS sheets or use the EPISUITE software by the EPA)

The way I look at is from a risk analysis. If, god forbid, I was rear ended severely in an accident, would I rather be sitting on gallons of a carcinogenic and flammable liquid that easily vaporizes or a solid that can easily be cleaned up and have no risk of breathing in?
The track record for gas powered cars isn't too good when it comes to that (the notorious Pinto, Crown Victoria police cruiser) I read a number of studies that said around 3,000 to 5,200 (number varies depending on the sources, but the numbers are on the magnitude) people die per year due to car fires caused by collisions, I'm guessing having a 50-150 lbs of gasoline fueled or at least contributed in some form to these fires.

I would much rather be sitting on batteries than gasoline. That is one of the things that convinced me to buy an electric car.

Yes they have been crash-tested and crashed in real world. Nothing to be worried about. Battery is much safer than gas-tank. There is no engine if front in Lotus Elise, most Ferraris, Porsches or Lamborghinis either. Roadster is no different than those cars for head-on collisions. In fact from real-world experience it looks like they are one of the safest cars of their size.

Only situation where gas-tank might be safer than big battery is submerged in water after a crash (something like dive from cliff to water after rear-ended by another car), but even then AFAIK battery has automatic safety mechanism that separates individual cells from outside so that you don't get electrocuted (even salt water is bad conductor for low voltages and fresh water is less conductive). IE. in very rare cases. Usually ICE-cars are less safe than EV:s.

Are there test video or cases?

I'd like to post them on fan site toyotatesla.com as well.

I know of two cases. There was a Tesla sales director crashing one in California a year or so back. I also recall an unfortunate soul in Skandinavia, who lent his buddy his car (just received it that week) and completely totaled it. I think he slammed into the rear of a 16 wheeler.

Amazingly no one was hurt in either incident, especially considering the pictures of the demolished cars

I felt that this may be relevant to the discussion about crash testing. This is an older blog, but a goodie!

http://www.teslamotors.com/blog/safety-first-ouch

Enjoy!

@TslaFan, Jerry, I have seen result of the case where Roadster was crashed behind and as a result of that it dived under a quite big SUV. Not nice, but all that happened was that car was totaled, Both front and back were crushed and apparently some cooling fluids were leaking (can't figure out what else it could have been). Battery itself was intact and driver didn't get hurt (much).

From denmark
correct, car was 1 week old - nobody was serious hurt.
see pictures here:
http://ekstrabladet.dk/biler/bil_nyheder/article1243890.ece

it was on the highway, tesla and VW was holding still due to highway que while the driver of the toyota prius was driving into a motorbike+Tesla - crashing further into the Tesla (witch was then pushed under neath the VW) - basicly both a fuel car, a hybrid car and a pure EV car was involved

My concern is the rear facing seats being so far rowards the back end of the car, would my child be safe in the event of a rear impact accident. What is the structural integrity of the rear of the model S?

Tesla's cars are subject to the same standards for car safety as any other being developed for the road.

Thus, they have to meet safety requirements before they're allowed to be built. Just like the roadster, the first couple prototypes will be used in crash tests, and the rear facing seats will be tested in a variety of crash scenarios.

For the record, several minivans already use rear facing seats, and old style British taxi cabs have been using them for decades. I think if there was a serious issue, it would have been determined by now.

If you think about it, with rearward seating, a car running into you from the back is usually going to be braking fast, and will usually hit the rear end of a stopped car. 30 mph or less. In a side crash, often the same scenario, only the speeds would be a little higher as the side car is planning on going through when the straight car blocks him. In a front crash, speeds are added, so two cars braking to less than 60 mph are going ~120 mph. That's how my daughter died. The airbags weren't enough. Rear facing seats are probably the safest place in the car.

You can't add the car speeds together in head-on collisions. Going 60mph in head-on collision is same as going 60mph in the wall. Then you need to calculate car mass in that mess. Hitting a mini with a truck is different thing than doing same other way around. If you are sandwiched between truck and heavy SUV in rear collision car is going to get seriously crushed.

But you are right that in rear-collisions speeds are usually much less fast and without that sandwich your car is going to move which helps the survivability.

Rear facing seats at the rear seats are the safest place to be. OTOH looking at Model S it looks like rear window will be *really* close to face of those rear seat occupants. It wouldn't take much to get their heads to hit it, which is bad. Also having glass that close to my face would make me nervous, and I would believe small children would get "range anxiety (tm)" very fast.

Hi, just wanted to add. Timo, in a head-on collision, the forces of either car are multiplied by the mass and their velocity (Speed and direction)...

To not get too technical, a 5000lbs car running head on into a 2500lbs car, the 5000lbs car would not see 100% of its inertial force transferred through its body. However, the 2500lbs car would see more than its velocity (inertial force) in that high speed impact. When the smaller car hits the bigger car, the smaller car takes more damage, as if it were traveling faster. The 5000lbs object slows down, while the 2500lbs object changes direction (theoretically).

Just to add... if the cars are identical -- or nearly identical -- in weight and size, you can effectively add the speed of both cars to get an approximate speed of impact...

Two cars that weight 3200lbs head on collide with each other and both are traveling at 35mph, that impact would equate to a 70mph impact. That "wall" of "equal and opposite reaction" is effectively traveling twice the speed of either car. so both operate under the same principle.

Hmmmmmmmmmmmmmm... I cracked open my old physics book to make sure I was indeed correct, and I am not HAHA! you are right Timo. I rescind my previous comments.

@SpecialK, your first point is correct, if you crash to cement-truck with tiny Fiat 500 while both are going 60mph then for that Fiat it is nearly same as crashing to wall at 120mph, and that cement-truck just keeps on going with just small speed drop. But if the cars masses are identical then it is pretty much same as crashing to wall at 60mph.

Piper;
Assume you meant "least" of your worries? Unless you have a "list" of maintenance issues ...

:D

I'm suspecting that Pipers message is hidden spam. It has no real substance, and it has nothing to do with the subject which is crashing EV. It is probably aimed to advertise that link stuff, maybe luring people to that site so that they get some money from advertisements.

Flagged as such.


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