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Bottoming Out

Discussion in 'Model S: Driving Dynamics' started by golfski, Oct 2, 2014.

  1. golfski

    golfski Member

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    This morning as I was slowly going over a speed bump in my work parking lot, I encountered a very powerful and loud "thud" on the underbody of the car. I have coils and have always been very careful when navigating any sort of situation when clearance might be an issue. I am not sure why I bottomed out, my tires are full and when driving over it later it was perfectly fine.

    I am worried about damage a single incident like this might cause. I got down on my hands and knees and couldn't detect any damage (scraping, dents, etc…), but given the fact the battery is underneath, just curious of any unseen damage this could cause. Should I be worried? Nothing seems to be wrong with the car (no warnings, drives the same, no visible damage) but it was pretty loud thud and it felt pretty violent.
     
  2. zwede

    zwede 2013 P85+

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    No worries. The bottom of the battery is very thick material and doing what you did will not damage it.
     
  3. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Should be no worries, I whacked mine in a parking lot with stick-out curbs--no problems.
     
  4. Todd Burch

    Todd Burch Electron Pilot

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    I bottomed out 3 or 4 times over 31,000 miles. Never saw or experienced any damage. And yes, it's quite a thud because you're driving a tank!!!
     
  5. lolachampcar

    lolachampcar Active Member

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    There are also rails that run the length of the battery that actually stick down just a bit lower. I've found that I land on these most every time and do not even contact the flat portion of the bottom of the battery.

    A tech at the SC did mention that there are some rub tell tails built into the construction of the bottom of the battery so it would be wise for all of us to be careful. Tesla has been very good about taking full responsibility for the car even with less than stellar attention to care on the customer side but I would not want to push our good luck too far.
     
  6. Zextraterrestrial

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    I bottomed out once on a rollercoaster-like vertical curve accelerating at ~ 60mph(no bump in the road or anything, just too much negative g's). that was harsh!

    should be fine, there are really strong rails along the sides of the battery area. engineered well
    (ya what lola said!)
     
  7. ecarfan

    ecarfan Well-Known Member

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    What do you mean by "vertical curve"?

    Do you have the highly coveted "SpaceX vertical booster" option?
     
  8. Blurry_Eyed

    Blurry_Eyed MS Sig #267, MX Sig # 761

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    I haven't bottomed out, but I recently ran over some road debris that was pike shaped and had it really impact the bottom of the car very hard. No damage to the battery or even the underbody aero shield (I did have Tesla retrofit the Titanium underbody shield on my car). It seems to be very, very robust under there, so I think you have little to worry about.
     
  9. Zextraterrestrial

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    funny you should ask, yes I do! oh wait, no, that was the option I passed on, damn

    I guess I should have said a vertical curve with a positively increasing slope. like a big dip. I was driving downward/accelerating at close to a 0 g feeling speed and then the road curves up
     
  10. William13

    William13 Member

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    twice rubbed speed bumps and once bottomed out on a country road. I no longer use the auto lowering as I use country roads.
     
  11. donv

    donv Member

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    There is a specific speed bump where this happens to me, in the parking lot of my daughter's school. I don't really understand it, because it doesn't seem that high (my Porsche Cayman, which is much lower than the Tesla, negotiates it with no problem). I need to try raising the suspension next time, I guess. It's only an issue with the rear wheels.
     
  12. dflye

    dflye S Sig Perf 414, VIN 814

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    I've actually managed to get the car completely high-centered while attempting to turn around at night on a friend's very dark country driveway with what turned out to be a much steeper shoulder on one side than the other.:crying: Even raising the suspension didn't help raise it enough to get back up the slope, so we let gravity finish the work (after removing the rails on a section of fence) and pushed it a bit to get it to roll down the slope into his pasture to complete the turnaround (and escape via removal of another section of split rail further down the fence where the shoulder was more level)

    Took the car to the service center the next day, and while the encounter with the pavement had chewed up the edge of his driveway, gnawed off a few good sized sections of the plastic covering over the metal rails that are meant to protect against this, and scuffed up the metal rails a bit as well; car still got a clean bill of health: the rails did their job! Thankfully it was just cosmetic damage in a location you wouldn't see unless laying on the ground beside the car. :smile:
     
  13. Pate

    Pate Member

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    I also once bottomed out when backing out of a parking garage I occasionally visit. During earlier visits I had manually raised the suspension, but on this occasion I simply forgot. I still had 5.9 firmware at that point. Pretty scary loud bang...

    Since I got 6.0 firmware the location-based auto-rising has handled this automatically. I am extremely happy with the 6.0 firmware, simply because of this feature!
     
  14. 3mp_kwh

    3mp_kwh Member

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    Bottomed slowly, entering a parking garage this morning. I'm currently at 'Low' equivalent height, and it was simply a steep down slope that did it between the front/back tires. I had expected a typical nose, or tail, bottoming would be where I might have an issue. Even at 'Low', the MS clears places the Volt's front apron does not. The surprise, as others reflect, is that it is between the front/back. This is a place where I don't think a longer wheel base helps. I'll be sure to crab my way out.
     
  15. nictw

    nictw Member

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    I was letting a friend test drive the Tesla and the car did not automatically raise in a location where it usually does.. I did not catch it on time and over a tall bump we heard a hit.
    I went to service and they told me no damage, just a scratch.. see picture... Screen Shot 2015-10-13 at 12.56.15 PM.jpg
     
  16. supratachophobia

    supratachophobia Active Member

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    I did the exact thing, once. Service and I couldnt find a single blemish when we raised the car up on the lift. But darn if it wasnt loud when it happened.
     
  17. vgrinshpun

    vgrinshpun Active Member

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    #17 vgrinshpun, Oct 14, 2015
    Last edited: Oct 14, 2015
    Construction of the battery pack is very robust. I think it will take occasional bump/hit in stride. Below is the drawing from one of the Tesla patents for the construction of the battery pack, annotated by me for a presentation about EVs and Tesla that I did a while ago, based on the description in the Patent (all elements were numbered - I replaced the numbers with the descriptors). The only remaining number -901-denotes individual battery cells.

    Note that on the bottom the battery pack is protected by ballistic shield - 1/4" thick aluminum plate, which is separated from the bottom of the pack by at least 2" of the compressible material (terminology and thicknesses verbatim from the patent). The idea behind the compressible material is several fold:

    • to prevent penetration of a sharp object through the ballistic shield (as an example try to use pencil to poke hole through loosely held between two hands piece of paper, and then repeat with a tightly held piece of paper - it is much easier to punch hole through the tightly spread paper)
    • to absorb bland force impacts before the stress is transferred to the battery pack.
    • to provide thermal insulation

    The bottom line is that I do not think that OP has anything to worry about.

    Snap100.png
     

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