Support Tesla in finding a solution from those random metal debris.

Support Tesla in finding a solution from those random metal debris.

We know that sports car tuning or air suspensions lowers the Model S at high speeds to improves aerodynamics and increases range. Lets face it, a lowered vehicle traveling at high speed, whether it's a Model S or a Lamborghini, vs a random trailer hitch or a bent metal pole on the middle of the road will inevitably cause damage to the under-body. I should know. In my younger years, I had a drop rice rocket with a clearance of 2-3 inches from the ground. I had my share of damaged bumpers and under bodies by merely going over speed humps.

I really think this is simple fix for Tesla. Have a sensor in the front that will scan for any large debris with the potential to go under the vehicle. Once the sensor senses a dangerous debris, a deflector shape similar to a snow plow on trains pops down under the front bumper. The deflector then drops down as close to the road as possible to maximize the deflection of the debris away from the center under-body, away from the front wheels and away to the side of the vehicle. It may not be 100% effective but at least the deflector will deflect any debris from hitting the vehicle's under-body where the battery is located thus minimizing damage and ultimately fires. After a couple of seconds deployed, the deflector then pops back up into the front bumper and resets preserving the aerodynamics. A service vehicle warning will then pop up in the display screen inside the cab to let the owner know to take the vehicle in for service. Obviously, this fix should be an add on piece that can be attached by taking the front bumper off and mounting it to the front frame. This add on piece can allow Tesla to recall all the Model S currently on the road for installation. I'm no mechanical engineer, but I am sure Elon has the best and brightest to work out the specifics. Fellow supporters of Tesla. What other ideas can help?

Long time support of alternative vehicles. Go Tesla!!

stevenmaifert | November 8, 2013

I'm not sure your solution is even technically possible. Even if you could sense the oncoming of road debris, could such a system deploy in time when you are traveling 100 mph plus on the autobahn? What Tesla could do right now, and I mean RIGHT NOW, is to get an emergency software update out there that allows owners with the air suspension to de-select the lowered "crouch" at highway speeds, thus allowing for more underbody road clearance. We do that at the cost of a few miles of range, but that's a small price to pay if it means not suffering a catastrophic fire from striking something in the roadway.

jonlivesay | November 8, 2013

I usually just look forward when driving and pay attention haven't hit anything in years

elephant in a bottle | November 8, 2013

+1 Steven
A nice way also to showcase the "over-the-air" service updates that Teslas have.

To add, give driver ability to raise the car to highest clearance as possible. Could be useful also if you get into rough terrain.

stevenmaifert | November 8, 2013

jon - That's good for daytime driving, but when traveling at highway speeds at night, by the time your headlights illuminate an object in the roadway and your brain processes it as a hazard to avoid, you don't have much time to react.

elephant in a bottle | November 8, 2013

OTOH, this maybe some knee jerk reaction .. the 2nd incident seems real .. but could the 1st and 3rd incident possibly been a setup?
(conspiracy theories abound!)

Can a model S detect whether the driver was actually "inside the car" when the battery got punctured?

vraptor | November 8, 2013

+1 jonlivesay

Jon has the right idea. 15 years driving and I've only hit one thing in the road before, a huge deer carcass that there was no way to stop or swerve and miss (safely at least).

Raising the clearance would help as well, that and reinforcing the underbody plating. But I have to wonder, what is this "debris" they are hitting? It must be pretty substantial to be piercing the batteries.

elephant in a bottle | November 8, 2013

True as well.. 400k+ miles driving.. never hit a tow hitch nor an amputated bumper!

stevenmaifert | November 8, 2013

elephant - True. Most of us drive a lifetime with the crap in the road passing under our cars without incident. The fact that it has happened twice in five weeks with a ModS suggests... well, I don't know what it suggests, but it's unusual.

jajabor | November 8, 2013

move the battery pack 3 inches higher and add a second layer of protection under the car...this leaves few inches gap between the bottom layer and the battery pack.

Teslamark | November 8, 2013

I have a good amount of optimism bias for Tesla Motors. That being said I still think it is difficult to create even an unscientific causal relationship from two incidents within a random 5 week period. Extraordinary claims require extraordinary proof. Two fires caused by metal road debris in a random 5 week period don't appear to be extraordinary proof of a problem.

elephant in a bottle | November 8, 2013

I'm still very impressed at how MS "alerts" the driver to pull-over and leave the vehicle once it detects the battery damage.

The fact that MS already knows that the battery is compromised and also given the fact that the fire gradually intensifies..

Here's my 2c.
Could TM add a component that "extinguishes the fire" right at the moment it detects that the battery compartment is compromised?

It will behave in similar way like how an airbag works whenever crash happens.

In this way, minimizing damage to the car.

Webcrawler | November 8, 2013

The only thing that it think would work would a titanium plate in stead of aluminum. It is significantly more resistant to being pierced and is about the same weight, but a lot more expensive to manufacturer......

aaquino22 | November 8, 2013

I think that a built in fire extinguisher could be another solution. I know that the fire department uses a Carbon Dioxide canister that extinguishes electrical fires by displacing Oxygen, but first and for most, the charge has to be cut. That would be hard to do with batteries.

I was just thinking conspiracy theory the other day. I for sure haven't run over a large metal object in the middle of the road through the decades of driving. I see Big Oil as the culprit. Let me see, by 2015, there is a car made by Tesla that will allow people to travel across the country and north towards Canada for FREE, sponsored by the sun. Tesla just opened pandora's box. But screw big oil. Tesla is not alone. I'm still going to buy and invest in Tesla and I've spread the word to all my relatives and friends. If anything, big oil SHOULD be scared.

donwillner | November 8, 2013

187,000 cars caught fire in the U.S. in 2011--that's approximately 512 vehicle fires a day. The media isn't interested in those. Tesla is new technology and is in the limelight, so this story makes good press. What's key here is something a friend of mine said who is a Fire Chief in Alameda County, "I see car fires all the time. What's important here is that in all of the Tesla cases, the driver was able to safely walk away from the vehicle."

Captain_Zap | November 8, 2013

@elephant in a bottle

Are you implying that it might be more than a coincidence that the Model S fire happened within 4 miles of the Nissan Leaf plant?

aaquino22 | November 8, 2013

That's a good point Don. I don't think our current cars give a warning to the passengers if the gas tank is going to blow. If it blows, it blows.

elephant in a bottle | November 8, 2013

I thought the same thing.. :)

just an allusion | November 8, 2013


+1 Yes, short of integrating a cow catcher killbar into the front clip...

...altering the highway ride height, while a sacrifice to the overall attainable mileage, would be the quickest, zero expense fix for the issue that would serve to immediately circumvent the potential for the issue reoccurring.

Then there's also the argument for commuter roadway situational awareness, though the frequency of the occurrence of the issue, coupled with the timing, IS somewhat conspicuous/suspicious.

Brian H | November 9, 2013

Raising the floor is not an option; there's little enough "foot room" vertically already. The whole car would have to be raised.

Timo | November 9, 2013

@Webcrawler, battery bottom is steel, not aluminum. Very durable already, puncturing it requires a lot of force. Force enough to puncture any ICE car floor.

dz4 | November 9, 2013


I think your post is brilliant, but the solution you are suggesting is adding too much complexity to the problem.

A better way to approach this could be to accept that rare debris events could happen, and focus on preventing or minimizing the fire that results from it. If the firefighters take 5-10 minutes to get there, and you delayed the fire from spreading for 5-10 minutes, you solved the problem.

What are the parameters of the problem? you want a fire suppression system that is automatic, as lightweight as possible, takes as little space as possible, can reach any part in the bottom of the car and is reasonably cheap. If you could come up with such a system you solved the problem.

donaldmeacham1 | November 9, 2013

All of the attention to the three MS fires is entirely a media event. It they occurred in any other vehicle I dare say we wouldn't even know about them unless they involved us personally or occurred in our neighborhood. Repeating what many others have said there were no injuries of fatalities and and the passenger compartment wan't violated.

dz4 | November 9, 2013

I'm thinking, a best case solution could be one that uses technology that is already incorporated into the car. Could the cooling system be dual purposed as to act as a fire suppression system during an emergency? Does that even make sense? Is it something perhaps already implemented?

stevenmaifert | November 9, 2013

Newton's Third Law is at work here. When you hype your car as the safest in the history of the planet and win everybody's "car of the year" award, you generate a lot of media buzz. Conversely, when you have three battery fires in five weeks suggesting that maybe the car isn't quite as perfect as we've been led to believe, that's going to generate media buzz too. What's important is that the reporting be fair and nobody draws any premature conclusions about the safety of ModS.

x.tyrkalo | November 9, 2013

Dear Elin Musk;
In consideration to a recent battery fire I submit reformatting the layout of the protective battery plate and an implementation of a plate pressure sensor array. My design would incorporate multiple layers of composites and or metals in the new engineered protective battery cover with semi-spherical corrugated plating sandwiched between. As the plate is pushed up by said road debris to maximum set load the car would adjust the suspension and speed allowing the debris to release without exploiting the integrity of the lithium ion cells. Together the two systems should fix the battery puncture problem. As I piece this together in my head I can see the potential form factor may be slightly larger and lighter than cast formed aluminum but would greatly increase impact resistance. The initial design could be fabricated and outsourced quickly and implemented in a relactively short time span.

With all that being said I've watched Tesla Motors grow from beginning. I am happy that there are more people in support of alternatives for the transport/ energy industry. Although I'm just an electrician and may never be able to afford a super car to the standard of the Model S. :( I Hope my idea helps.

Thank-you for your time and attention.
Xtopher | November 9, 2013

@Timo - The bottom of the battery is a 1/4" thick aluminum plate with steel rails. Just go under the car with a magnet and you can see where the steel is vs the aluminum. The steel rails are lower than the battery pack and should often take most of the impact.

While there are a lot of interesting armchair ideas, I really think the current design is more than adequate. Every safety system is designed to protect the occupants and if the car is destroyed (crumple zones, rollover, fire, etc.) and you can still walk away unhurt, the car has done it's job. I'd much rather have a slow battery fire that doesn't enter the cabin than an explosive gas fire that has a high potential to quickly incinerate the passengers!

Trying to protect against exceptionally rare events is always possible, but you add cost, complexity, and may even reduce safety for some other events. For example, let's take the OP's idea of rail that drops down. If the object is big enough it might rip off the drop down rail and drive it into the battery pack! How large of an object do you try and protect against? What size and shape? What if the object is propelled at you from a vehicle in front of you?

I come back to the thought that we really shouldn't care what happens to the car so long as occupants are protected. Since it appears the Model S protects it's occupants better than any other car out there, I don't see any design changes as necessary.

Lastly, let's say you want super protection. You could install your own 1/2" steel plate to the bottom of the car, change the suspension and make other needed modifications for perhaps at a cost of $10,000. It may add another 1000 lbs to the car, and that would eliminate the ability to carry passengers and cargo. Range would also go way down - but now you now are prepared! While your are more likely to get hit by lightening, you'll have a car than can drive over anything!

Timo | November 9, 2013; The bottom of the battery is a 1/4" thick aluminum plate with steel rails

I stand corrected. Maybe it should be steel all the way? It would weight more than aluminum, but I don't think it would add much to overall vehicle weight if you don't go overboard with the protection, and it should be harder to puncture. It should also make a battery a bit stiffer so maybe you could get some of the weight back by reducing other supporting structures inside it.

dz4 | November 9, 2013,
While I agree these are rare events and by themselves do not require any dedicated measure, both in terms of price and safety.

But markets are not completely rational, and that changes the nature of the problem.

First, just the connection of 'Tesla' and 'Fire' in the headlines is damaging to the brand. Over the long term some of this mud could stick, and people will rethink buying an electric car.

Second, you have a vulnerability once people observe a pattern - a Tesla catches fire, then the stock dips. So, one could potentially short sell the stock and then burn a Tesla. This is to say nothing of the two accidents so far. But it makes Tesla vulnerable for such schemes.

Timo | November 9, 2013

It's three accidents now. That's nothing radical, but there was also news about iPad exploding here and when people read that and remember that Tesla uses laptop batteries they make conclusions that are not quite fact-based, but not that far from truth either. Those batteries can catch fire, they are not inherently safe, just safe when used properly.

They just forget that gas in their gas tanks is not safe either, so batteries are a lot safer relatively speaking. People get scared about news and forget that it's all relative.

elephant in a bottle | November 9, 2013

How about adding an anti-matter debris zapper? :))

Kidding aside, MS is has done its job exceptionally well in all those 3 incidents.. protect people's lives ! (and reminded them to pull over, no ICE car will ever tell you that their car is about to explode :))

In my mind, Tesla Model S is the "perfect" v1.0 supercar!

I see this more of a driver-training issue, or better, driver-error due to lack of understanding of MS features.

1. Instant acceleration -- like 99.9% of drivers out there no one knows how to drive this beast .. its an out of this world experience driving an MS! Avoiding road debris can be very tricky with MS!

2. Sophisticated Air Suspension - Do people know they can raise their clearance up to 7.9 inches (Camry's are like 6.1").. Do drivers understand how to use this feature?

elephant in a bottle | November 9, 2013

errata .. "MS has done"

jensjacob | November 9, 2013

I don't know too much about the aerodynamics below a car.
Is there a big difference between having a very low car vs. just a low front spoiler and side spoilers close to the road surface and a higher clearance between the road and the underbody as such.
If not, then the clearance under the car could be set to 'normal' alowing for safe passage over certain size debris like other cars and have spoilers maintain low underbody drag. Then if debris is encountered it will pass under the car only damaging the front spoiler.
The front spoiler could perhaps be made by some whisker like brush with hairs that allow debris to pass under the raised car but keep air turbolence away from under the car.

Brian H | November 9, 2013

It's Elon, not Elin.

Just as the "crumple zone" sacrifices the front of the car to absorb forces that would otherwise harm occupants, the limited vulnerability of the battery, with its so-far-perfect occupant protection features, is a "structural sacrifice" that it is neither necessary nor desirable to evade. A perfectly rigid bottom is also a perfect force transmitter. In a high-speed crash, something's gotta give; better a totalled battery than a totalled passenger compartment.

Charlie K. | November 9, 2013

The first fire was caused by an extremely improbable "pole vaulting" effect (as Elon said it) resulting from an oblong piece of metal getting stuck in the road. The second occurred because the driver drove into two walls and then a tree. The third was caused by a protruding trailer hitch. Let's get something straight; accidents happen, and it is safe to say that these events were clearly extraneous.

Good engineering involves planning for failures. The safest cars in the world are not the ones that are invincible, they are the ones that fail in such a way that the occupants of the vehicle safely escape. That's why the Model S is the safest car in the world.

The question is not "how do we fix the Model S", the question is "can they design the Model X (and the Gen III) to the same standards". This is, of course, a silly question because we're talking about Tesla, so the real question is "when will I be able to afford one".

levi.maina | November 9, 2013

Its now evident that MS has a soft underbelly at highway speeds of 60-80 mph. The under armor plate is not strong enough at these speeds...its venerable!

Here are 3 things that must be done to protect it:-

1. IMMEDIATELY:- All MS cars should have a cutting-edge (SMART-AIR-SUSPENSION) installed. These suspension should be integrated with a stereoscopic camera like the one on a 2014 MB S550. This camera scans the road ahead and adjusts the suspension in milliseconds whether its day or night...lifting the MS to original height of 7.9 inches to clear any road debris.
If the debris is bigger than original height it applies
the brakes & warns the drive AUDIBLY, to swerve around.
It could help if MS had blind spot monitoring so if there's no car in either side the car automatically changes lanes.
It will be easier to add SMART-AIR-SUSPENSION to owners that did not order them, than recall and redesign the entire car. THIS FEATURE CAN BE SENT AS AN OVER-THE-AIR UPGRADE!!!! no need to bring in the car.

2. Redesign a new armor plate and test it at 60-90 mph...because these are the actual speeds pple are driving on the highway. Material suggestions include Graphene and the newly discovered Carblyne(the hardest material known so far) also the lightest!!!

3. Integrate a chemical fire extinguisher esp at the front of the automatically spray the short-circuit in the battery..just like the air bag explodes during an accident.

4. This is a bonus ... use a solid state battery that never exploded like SEEO's

note: I am an engineer

aaquino22 | November 9, 2013


Do you have a link to SEEO?

Thank you! Solid state batteries is the future folks. I know of another advance battery in the works. ORNL has discovered a solid state lithium sulfur battery that is less fire prone, cheaper, lighter and holds 4x the kWh capacity as the most advance batteries. It's undergoing patents right now. I hope tesla is looking to adopt this technology. If it does, time to invest more money.

aaquino22 | November 9, 2013

A 1200 mile range Tesla Model S. Peace out ICEs.

Brian H | November 9, 2013

All nonsense. And how can the MS be venerable when it's barely a year old? "I usta couldn't spel enjinear, and now I are one!"

crazybrit | November 10, 2013

Add me to the list if folks that think the car behaved exceptionally well under the circumstances. None of the occupants were in danger of getting burned, they all walked away, and two of the owners said they plan to buy another Tesla. Fires tend to kick up emotion, but if the fire is contained, it is not an issue. Let's hope that as more accidents happen, this excellent track record will continue.

albert capelet | November 10, 2013

The most important thing is that no one was hurt, the gift is very simple we continue to share our collective experience. We continue to learn and advocating for change. I really enjoy reading peoples problem solving strategies some of which could easily be patent or better IP. Your biggest mistake is the one you let get away, I did not see any mistakes here.

Truly. Albert

ronnussbaum | November 10, 2013

Perhaps it is only coincidental that these happened so close in time, but one wonders if the conspiracy( big 3 or big oil)is the real reason.

stevenmaifert | November 10, 2013

There's medication for thoughts like that.

SamO | November 10, 2013

Tesla needs to advance driverless/autopilot systems which will sense debris.

Jewsh | November 10, 2013

@Brian H:

I agree that the ideas put forth by Levi are unlikely to go forward, but I'm sure you'll agree that being polite is extremely important on the Tesla forums.

TimC | November 11, 2013

My first thought aligns with Levi's second point and that is to add some kind of shielding to the underbody of the battery pack. It could be composed of Kevlar or some similar material. For whatever the material is, it would have to be practical in terms of cost and weight and able to withstand the "catapulting" forces described in the first incident.

Iowa92x | November 11, 2013

Kevlar blanket, done.

ashwin.jhavar | November 11, 2013

The chance for debris to hit is highest in the bottom front of car. One way to minimize the chance of fire would be to remove a few rows of good battery cells in the front and replace them with dead cells. These dead cells will take the impact and shield the active cells behind them. This will reduce the range though.. but could be a stopgap solution.

NikolaAC | November 11, 2013

Tesla should explore the auto activated fire extinguisher method, but using halon. Halon is non-toxic doesn't leave residue, is used where sensitive equipment (computers, etc.) is used. Additionally, maybe adding a layer of kevlar mesh to increase the strength of the aluminum shield?

PorfirioR | November 11, 2013

I have been thinking about the two road debris accidents and wanted to share my thoughts. In both accidents, the debris seemed to have exhibited an upward lever effect (a.k.a pole-vault).

Trying to imagine the dynamic forces involved, I picture the car driving the debris into the pavement, which then caused it to act like a spear. Ironically, the debris ends up going into the pavement because the battery plate is too hard to give first. Under such a scenario and with the speeds reported, no amount of strengthening would protect the underside of any vehicle.

Then I tried to imagine how the scenario of the debris becoming a spear trap could be avoided. None of the options seemed attractive or they create their own problems: moving/redesigning the battery, making the protective plate stronger, raising the car, etc.

Let's face it, the real problem is the rather un-photogenic failure mode resulting from these incidents. It is just bad press. The negative outcome is economic (which would be the case for any vehicle) and of reputation (therein lies the rub). There is no negative outcome for safety - on the contrary.

The toughest thing to accept for some people is that the likelihood of these catastrophic road debris events is so low that the most sensible approach may be to simply do like any driver of a corvette or other low-riding vehicle does, and accept the risk. Those drivers know that, if you run over a large metal object, your car will be damaged, sometimes severely.

Then there's this:

Drive safely folks.

Brian H | November 11, 2013


I note that driver in your eg vid was <1 sec behind those trucks. Bad idea.