Tesla Model S Gets Titanium Underbody Shield, Aluminum Deflector Plates 314
An anonymous reader writes "Tesla Motors made headlines several times last year for a few Model S car fires. Elon Musk criticized all the attention at the time, pointing out that it was disproportionate to the 200,000 fires in gas-powered cars over the same period. Musk didn't stop there, though. He's announced that the Model S will now have a titanium underbody shield along with an aluminum bar and extrusion. He says this will prevent debris struck on the road from breaching the battery area. Musk offered this amusing example: 'We believe these changes will also help prevent a fire resulting from an extremely high speed impact that tears the wheels off the car, like the other Model S impact fire, which occurred last year in Mexico. This happened after the vehicle impacted a roundabout at 110 mph, shearing off 15 feet of concrete curbwall and tearing off the left front wheel, then smashing through an eight foot tall buttressed concrete wall on the other side of the road and tearing off the right front wheel, before crashing into a tree. The driver stepped out and walked away with no permanent injuries and a fire, again limited to the front section of the vehicle, started several minutes later. The underbody shields will help prevent a fire even in such a scenario.' Included with the article are several animated pictures of testing done with the new underbody, which survives running over a trailer hitch, a concrete block, and an alternator."
"extrusion"? (Score:0, Interesting)
Re:Sounds like (Score:5, Interesting)
The Tesla Model S sounds like a tank. I needs a tank to traverse these pot-hole-riddled roadways. Where's the ammunition stored?
The combination of low profile tires + being low to the ground just doesn't handle that kind of stuff very well. You'd probably have to raise the suspension a little and replace the wheels with something that can handle higher sidewalls. I have a friend who owns one and he's had to replace two of the wheels (the entire metal wheel, not the tire) due to hitting fist sized rocks in the middle of the road that bent the rim. I'd imagine that a pothole might have the same effect.
Re:Sounds like (Score:4, Interesting)
Lots of cities are like that in the US these days. Sad, really. And that's not even including Detroit, which is starting to look like a Mad Max movie.
I looked at the Tesla before I bought my current car, but the Tesla isn't really a luxury sedan despite the price (nice ride, though). One important consideration for me was practical wheel size and ground clearance. I don't need offroad tires, but a ~50 tire aspect ratio and reasonable ground clearance let you take pot holes and stupidly-steep ramps from streets to parking lots at a reasonable speed without fear of damage.
Ribbon-thin tires are just asking for trouble. Plus even the rap songs acknowledge "rims too big make the ride too hard".
Re:"extrusion"? (Score:4, Interesting)
Extruding aluminum tends to be stronger than cast aluminum. I imagine 3-D printed aluminum is not as strong not to mention it is a lot more expensive and much faster.
Re:Very amusing but... (Score:5, Interesting)
>You have to manage an inventory of expensive $20k+ parts that could be stolen,
All inaccessible and underground. They're also fairly useless to thieves; who would they sell a stolen Tesla Model S battery pack to?
The battery packs are heavy, unwieldy, and can't be resold to anyone. If you're a thief, there are much better targets.
>you have multiple sizes and model of battery,
All the loaner packs can be the same size and model.
> and different wear states. The batteries lose power constantly.
Since they're at the charging station, they can keep the batteries topped off. As they wear out, they'll be replaced. Tesla owns the loaner packs. The battery swap is actually a loan, not a true swap like propane. You have to go back to that station and get your original pack back.
>You have to manage liability, if you install a defective battery and it catches fire who pays.
Tesla, since they're both the manufacturer and the battery swapper.
>You have complicated machinery that you need to have many of to handle rushes that go unused at other times
It takes 93 seconds to swap batteries. http://www.teslamotors.com/bat... [teslamotors.com]
They really only need one swapping machine on site for the foreseeable future, and if they get to the point where they need more swapping machines, then they're doing very very well.
Especially since swapping isn't going to be used day-to-day; you'll charge at home or work. Swapping is really only for long-distance trips.
>And you still need to have the same order of magnitude of power available to charge up the swapped out batteries as you would to just charge them in the car.
Of course. The advantage of battery swap is that you can run out your current battery, swap at the station, drive wherever you're going, come back, swap back for your now-recharged pack, and go home. 186 seconds during the trip, versus having to stop and charge for a few hours.