What Happens When Sparky Car Sits In A Puddle?

While I don’t know how deep the water was, and they do say it was in the water for 10 days, I’m not keen on the idea that when your Sparky Car gets wet you need a new motor…

It’s interesting to see how the thing is put together. Also of interest is that the thing is not entirely water proof and the inverter is in one of the “cans” off of the differential with the actual motor in the other “can”. I’d have put the inverter somewhere else, and had it entirely sealed. But then again, I’m not a genius like Musk…

So without further ado: When Sparky Car meets Big Water:

Now the other unsaid question is just how long until a lethal level of water gets in? Is it “drive a block” with water over the motor (about 2 feet deep?) or is it 10 feet under for a week?

I know I’d not want to own one of these in places prone to any amount of flooding…

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
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21 Responses to What Happens When Sparky Car Sits In A Puddle?

  1. H.R. says:

    I finally got a chance to watch the video last night and that was quite a bit of water intrusion.

    In my pre-retirement life, we had a lot equipment that was exposed to cutting coolants and one that was continuously sprayed by an alkali pre-paint combination cleaner/phosphater. Here’s a link to a washdown motor that some might be familiar with.


    We have a koi pond with three pumps, which remain submerged and running until the pond freezes over. They fail after 2 to 4 years, sometimes due to wear and sometimes due to water intrusion (all the pumps run from GFI outlets so we don’t have an inadvertent fish fry 😜).

    The point being that electric motor sealing technology is old stuff, so I am guessing that Tesla designed that unit based on the assumption that it only needed to keep out moisture. As can be seen at the beginning of the video, the cover plates they removed completely protected the motor from spray when driving through rain.

    From the video, it seems Tesla did not design for submersion. I would not be surprised if there’s a warning in the Tesla Owner’s Manual to never drive through standing water.

    There are some sedans (Mercedes, I think?) with door seals sufficient to let you plow through water for a short distance, say a flooded intersection, as the electrical components are generally higher up for access. I’m not sure that a Tesla would make it through a flooded intersection.

  2. philjourdan says:

    That was my first question as well – how long did it take for the water to seep in. I will pass on Tesla for now.

  3. H.R. says:

    @phil: “[…] how long did it take for the water to seep in.”

    Not long; possibly minutes. That’s what my babbling was all about. The cover sheets are the giveaway that the motor module needs protection even from spray. It looks like Tesla did think ahead to the cars being driven through a car wash with the undercarriage spray nozzles and expected it to be a problem. Otherwise, you’d leave the undercarriage open to provide additional cooling for the motor.

  4. H.R. says:

    Okay. I cheated and searched on “driving Tesla through water.”

    I found this in a comment on a User’s forum. The thread isn’t wordy, so it’s easy and worth it to read the whole thing.

    “If I recall correctly I believe the official answer from Tesla was that the fording depth for the Tesla was zero. as in not a single puddle. Now we all know this is a bit extreme, but it’s certainly the easy answer from them.”
    (emphasis mine)

    Here’s the link.

  5. E.M.Smith says:


    From what I see in the motor disassembly, I’d say that was about right. It just looks like the cables go down a hole with grommet like seal (i.e. not a pressed gasket) and any pressure differential at all will have seepage… into a 400 V box…

    I know I’m not nearly as much credentialed as whoever designed that thing, but were I designing an electric car, I’d have completely sealed oil cooled motor and the inverter / battery box either sealed or elevated above door height (that is, near the top of the hood covered area). Think your basic “bathtub” from below with a screw-on gasket cover. Heat management matters a lot, so you either liquid cool the whole thing or do air cooling with a heat exchanger (aluminum is cheap and a few pounds of it as fins with a fan blowing on it can move a lot of heat. Heck, just stick the fins out in the air stream from motion… IF you are using a lot of e- you ARE moving, right?)

    Then again, I grew up in “farm country” were occasionally fording a low spot or going out to the river was common and where levy breaks or heavy rains sometimes meant fording a couple of feet of water or not getting home. (And not getting home sometimes means getting washed away…) Hell, I’m nervous about my Mercedes 240 D not being enough and it is built like an Army Staff Car (’cause it was…) with “by inspection” the ability to ford about 3 feet of water. (floor would get wet through the ‘drain plugs’ but the running gear would keep working). I’m happier with the Subaru Forester as it’s built higher and 4 x 4 drive.

    Clearly I’m not the target demographic for the Tesla…

    In Texas there are frequent “low spots” where for a few hundred yards they have signs saying something like “floods in heavy rains” or “flash flood area” or some such. Basically, WHEN it rains a foot of water in an hour, the spot 2 feet higher stays drier and the water “leaves” to the river via those washes. It is COMMON to drive through a foot of water in those areas as long as you have the equipment for it. (i.e. truck or big domestic car).

    What this video tells me is that the Tesla is unsuited to Texas.

    You might be able to run one in the city (only) and only in good weather. But look at the recent weather from Brownsville to Corpus Christy. Whole cities with a couple of feet of water in the streets. This is unusual, but NORMAL. (i.e. infrequent but happens).

    It also tells me the Tesla is NOT your ‘getaway car’ for anywhere with hurricane evacuations.

    IMHO, designed in California for California. Maybe also useful in the Desert Southwest. (Wonder if there’s any data on what happens when it’s over 100 F …)

  6. E.M.Smith says:

    From that link:

    There are many parts that are properly sealed and those that aren’t. For example, on top of the inverter there is a breathing hole which will most likely let water in, and it has no where to escape..

    20cm sounds ok at a guess, but personally I’d try to avoid that.

    “Breathing hole” eh?

    20 cm is about 8 inches ( 7.87) which is effectively “nothing”… We’re talking your garden variety puddle.

  7. E.M.Smith says:

    Oh My! That thread is a gem of information:

    One guy says 16 cm is closer to the limit (or about 6 inches) then we have:

    Well, last time it rained in LA I was forced through a flooded road. Unknown to me sometime earlier I had struck road debris that cracked the battery pack… you can see how this ends…

    So… beware. $22,000 for a brand new battery pack

    So no road debris… Got it. Never drive anywhere that has not recently been swept… That leaves out the road in front of my home.

    See, folks pile “yard waste” on the street and the city picks it up with a sort of clamp/scoop thing. Unfortunately, they often do this without slowing down a lot. So we have the occasional chunk of tree in the street. Usually less than 2 to 3 inches in diameter and a foot or two long… but just long enough to poke hole in a battery pack… if it gets flipped up to ‘engage’ by the tires.

    Also, that $22k is more than I’ve ever paid for a car. Admittedly, I buy used cars, but then I tend to get a decade or two of use out of them and riding in an old Mercedes is not exactly a hardship. I figure I can get fixed whatever needs it for between $2k and $8K even for a really problem case But a $22k PART? Um, no. So this also says that at EOL for the battery pack you have EOL for the car. So what’s max cycles on a Li-ion battery? 2000 cycles? 2000/365 = 5.5 years? OK, note to self: NEVER by a USED Tesla over 3 years old… and expect it’s at most a 3 year life left. Figure $2000 / year value, so car max price $6000. That’s the MAX I’d pay at resale for a 3 year old Tesla with very good condition and a history of light use (i.e. not deep cycled 2 x daily to LA and back)

    So this is a city-only car, for dry roads only, recently swept with no debris, and only for “buy new and crush it in 5 to 6 years”. Got it.

  8. H.R. says:

    E.M.: So this is a city-only car, for dry roads only, recently swept with no debris, and only for “buy new and crush it in 5 to 6 years”.

    You left off, “For satisfying self-righteous egos only.”

    Still not quite ready for prime time.

  9. Larry Ledwick says:

    “Breathing hole” eh?

    Some auto differentials have breathing holes to allow pressure equalization but some of them also have a short piece of tubing attached to the breather so the opening is well above the axle center.

    I predict that Tesla will go through a learning curve (if they stay in the auto business) over the next decade or two finding all those little issues that lie outside clear flat pavement driving that real world users encounter from time to time.

    Of course if you live in an area like Palo Alto where a 950 sq ft house sells for over a million dollars and drive a $70k to $140K dollar car that battery pack price might sound reasonable.

    Per Wiki
    The battery is guaranteed for eight years or 125,000 miles (200,000 km in metric countries) for the base model with the 60 kWh battery pack. The 85 kWh battery pack is guaranteed for eight years and unlimited miles.[114][115] A poll among drivers indicate that accumulated battery loss steadies around 5% after 30,000 miles (50,000 km),[83][116] decreasing further about 1% per additional 30,000 miles (50,000 km). Unlike Nissan, Tesla does not specify a limit for battery loss, but some early battery packs have been replaced.[117][118] A separate battery replacement guarantee takes effect after the eighth year for the 60 kWh and 85 kWh batteries.[119] Lithium-ion batteries operate best at certain temperatures. The Model S motor, controller and battery temperatures are controlled by a liquid cooling/heating circuit.[120] Waste heat from the motor heats the battery in cold conditions, and battery performance is reduced until a suitable battery temperature is reached.

  10. philjourdan says:

    “It also tells me the Tesla is NOT your ‘getaway car’ for anywhere with hurricane evacuations.”

    I think that was made readily apparent last year during Hurricane Maria, where Musk had to ‘cheat’ the software so that Miamians could get out of the state on one charge. It is a town car. But even in towns (like under underpasses) there are spots that flood during a heavy rain. I would have a big problem driving what amounts to a 400 volt marvel super hero (or villain).

  11. E.M.Smith says:

    I’d be real interested in knowing if that 8 year wartantee is transferable or not…

    My guess is that it is like most car battery guarantees. Your “4 year” guarantee is pro-rated and when your battery dies at 3 years (as expected) it gets you a trivial discount IF you but the replacement from them. Essentially a lock-in on future sales.

    I’d also expect non-transferable. They don’t care at all about the used car buyer as they get no sales income from that, but they do get to sell parts.

    I note in passing that the video guys said the insides of the inverter were not a publicly available part – i.e. MUST go to Telsa for parts AND installation… I’d bet batteries are the same.

    Until there’s a 3rd party vendor of $2000 batteries this is a “crush when battery dies” car.

    I see the same problem in LNG cars. I’ve wanted to buy one for years (mostly for cheap commuting to local work). But the used ones typically had only a year (or less) left on the tank certification. Replacement tanks were about $4000. Why pay $3000 for a “good used car” that needs a $4000 part in a year? Recently they have moved the certification out to about 15 years, IIRC, so brand new cars only “go poof” at the 15 year point. Which sounds great to some folks I guess… but I’m driving a 38 year old Mercedes and loving it… so I guess my POV is different when it comes to vehicle longevity…

    The history of CNG used car value during the 6 to 8 year tank certification life said they dropped to about $1000 or scrap at certification point, and about $2000 in the year or two prior. Now the market for them has largely evaporated as the “Early adopters” who bought one and discovered very low resale value have not bought new ones. The local Taxi fleets (who had bought a lot – I’ve looked at a few ex-Taxis for sale at tank near-EOL…) have stopped buying them. They frequently did “airport runs” so the fill-up every 100 to 150 miles at the airport was not a problem for them. BUT at tank replacement they have all learned what a $4000 bitter pill that tank expiration can be.

    Expect the same thing with Sparky Cars.

  12. ossqss says:

    How is this company even still in business? How does a company that has yet to make a profit have a market cap of this size?


    This was quite humorous ;-)


  13. Stewart Pid says:

    Electric & hybrid batteries get the full warranty period no matter who the owner is at the time of failure and with Toyota it is full replacement under warranty. I think Tesla is the same and Tesla has been good with warranty work from what I have read as long as there was no commercial use of the vehicle. I had a Toyota Camry hybrid … 2008 and now my daughters car and going strong at 10+ years with a best ever mileage of 52 miles per gallon (imperial for us Canucks). The new ones supposedly will hit 60 to a US gallon but I would believe that when I see it. I think the hybrid technology is pretty neat and Toyota has the reliability nailed but I wouldn’t buy a pure electric at this time …. just too hard to stay warm in Canada when the temps hit that -20 to -30C range. I will look for a video of a Calgary guy on a 140 Km trip and over half the Model X’s power goes to heating at -26C and they are all wearing parkas in the car. I travelled the same day and 40 minutes into the trip my daughter asked for the heat to be turned down in a Honda Odyssey van.

  14. philjourdan says:

    @ossqss – How? Amazon did not turn a profit for the first 20 years of its existence (not quite that long, but you get the drift). Startups have lots of ways to bury profit so they do not pay taxes. That does not mean they are not going concerns. I suspect Musk learned a lot fro Bezos.

  15. Another Ian says:


    “IMHO, designed in California for California. Maybe also useful in the Desert Southwest. (Wonder if there’s any data on what happens when it’s over 100 F …)”

    What about dust penetration there?

  16. p.g.sharrow says:

    In the early days of powered personal transport, the Electric Automobile was on par with the IC Automobile for range and comfort and cost. Over time the electric lost out. In nearly all cases the electric just doesn’t fill the needs for dependable, versatile, personal transport. You just can’t beat Liquid fueled engines for the needed energy density and refueling ease as well as range…pg

  17. E.M.Smith says:

    In “about” 1961?” (hey I was about 8 years old and I’m remembering this now, you want to the MONTH? ;-) I was in the “carport” of the lady who lived one block south of me. She ran an “Antiques” shop. In her carport was an ?Edison? car. It was an electric model T sort of thing. She explained that it was an electric car, but needed the batteries replaced as they had died. She didn’t want to spend the money to make it happen.

    IMHO, nothing has changed since then.

    It is battery life and cost that has, and will, sink the eCar.

    Despite the lead-acid to lithium/ Ion transition, nothing has really changed.

  18. Another Ian says:

    That was also a feature of 32 volt battery bank house systems

  19. Larry Ledwick says:

    Speaking of Tesla they are laying off some workers and closing part of their solar operation to reduce the cash burn.


    Since he is pushing solar battery storage, I wonder if he is trying to broaden the market for his battery packs to try to reduce unit costs and get economies of scale.

    He also could be creating a way to recycle his automotive battery packs as they age, put them in a less demanding application like fixed location solar power storage and exchange the near end of useful life automotive battery with a new one, and rotate that battery pack to a lower current demand application?

  20. E.M.Smith says:


    I doubt he is going to put EOL battery packs into new product. Part of how the system works is a computerized log of each cell and automatic removal of a failing cell from the active set. Over time, too many “dead” cells accumulate and the whole battery announces it needs replacing. (Per an IEEE presentation in Palo Alto by their Engineering manager back when they had ONE roadster to demo).

    So at the time of removal, there would be insufficient cells active to sustain operation at prescribed volts and amps. One would need to remove the cells, sort good from bad, and reconstruct. At that point, the value / cell is less than the labor to remanufacture. It would be cheaper to just build new (and ship the old off to the refinery to be melted / refined).

    Remember that the core motivation for all things Musk is a Mars Colony. “The Boring Company” to develop the tech to make underground tunnel based shelters. The Tesla to make vehicles that do not need oil. The rockets to get there. The solar panels to power the whole thing (and the big batteries to get you through the Martian night). Everything he does is just to find a way to leverage that development with selling something plausible to the rest of us or to collect subsidy money for his end goal.

    So IMHO his “house battery” is just another part of that. Just needs to sell enough to fund his development and debugging and build enough factory to make what gets shipped to Mars in 2030…

  21. beng135 says:

    When I worked at a power plant, the condenser well accidentally got flooded (somebody left a valve open after a brief outage), the condenser well-pump w/a 550V motor kept running under water! Of course after discovered, things were shut down, the condenser well was pumped out and the motor dried out, but didn’t need anymore more attention.

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