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Regen single failure?

Discussion in 'Model S: Driving Dynamics' started by scaesare, May 28, 2013.

  1. scaesare

    scaesare Active Member

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    Have had my car for four days and once the regen suddenly "let go" as I was decelerating. The car just went to "free coast" mode. The dash needle went to neutral. No other warnings or indicators. I didn't touch any other controls.

    It's not happened since.

    Anybody else have this happen to them?
     
  2. Rla

    Rla Member

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    Do not have the car, but heard that once the battery pack is 'fully' charged (might not = 100%) the regen no longer has the capability to store the energy, so there is no regen happening.

    Might that have been possible? Did you start with a 'full' battery, and had more regen than usage? (going downhill?)
     
  3. Todd Burch

    Todd Burch Electron Pilot

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    I've not seen this myself, nor have I heard of it happening to anyone else.

    1. Are you absolutely positive you did not knock the shifter to neutral?

    2. Any warnings or indications on the dash?

    - - - Updated - - -

    Probably not it. Not only would you see a dashed line showing the max regen limit, but you would've at least had *some* regen unless your battery was absolutely, positively, as full as it could be. Since you were in the middle of driving, that's not likely.
     
  4. djp

    djp Roadster 2.0 VIN939

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    Regen is also disabled when Traction Control engages. I've had this happen in my Roadster when hitting a bump in the road or loose dirt while decelerating. Regen cuts out and the car coasts for a bit before TC disengages and regen kicks back in.
     
  5. Doug_G

    Doug_G Lead Moderator

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    My Model S has never done that, even in the very places where my Roadster does it pretty reliably. Has anyone seen that actually happen in a Model S?

    Most likely scenario is you accidentally bumped the stalk into neutral. All it needs is a clumsy hand or a brain fart (e.g. absent-mindedly thinking it's the cruise control... I actually did that once!).
     
  6. scaesare

    scaesare Active Member

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    Interesting discussion... I'm positive I did not do this, as I would have to hen have shifted back in to Drive to continue, which I didn't.

    I also don't think it was a likely place where TC would have kicked in. Dry pavement, moderate speed, straight ahead.

    Odd.
     
  7. William13

    William13 Member

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    A bump in the road will disable road traction and the the regen turns off. I have it happen crossing railroad tracks or other bumps.

    This happens in Prius and Model S.
     
  8. Beavis

    Beavis Signature 991

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    Could you have possibly touched the accelerator and brake pedal at the same time? They are close together.
     
  9. youlikeadajuice

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    I'll second this...the roads in NY/NJ are awful and I've noticed regen cut out very briefly.
     
  10. Zythryn

    Zythryn MS 70D, MX 90D

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    The only time I ever experienced this (12k miles and counting) was the one time I accidentally shifted into neutral.

    If you are positive you didn't do this, note the time, call your service center and have them run the logs.
    Should be pretty easy for them to find out what happened.
     
  11. scaesare

    scaesare Active Member

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    #11 scaesare, May 29, 2013
    Last edited: May 29, 2013
    I appreciate the thoughts. I'm pretty sure I didn't induce it by pedal or lever action (but hey, I could have not noticed the pedals I suppose... but the shift lever I would have had to shift back).

    Based on some of the experiences posted, I suspect TC may have indeed done it. That having been said, if TC kicks in, I'd like to see a dash warning similar to what my Toyota does. All of the sudden having regen braking cut out completely when you are used to it's "normal" behavior could cause an issue.

    I'll keep an eye on it...
     
  12. FreeOfPge

    FreeOfPge Member

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    There is previous discussion on the board someplace about this problem. Yes, it seems to be an issue with regen on electric vehicles. It primarily happens when hitting a bump or pothole. It happened to me one time while traveling about 25 mph as I approached a stop light and hit a pothole in my 2011 Volt. I can not remember for sure if any leaf owners have reported this. Leaf owners, please chime in here.
     
  13. PhilBa

    PhilBa Active Member

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    This is a disadvantage of having regen tied to the accelerator and not the brake. While it's an uncommon thing (battery full, regen stops) most of the time, it's something that every Tesla driver should be aware of. I am getting my MS in a couple of weeks so haven't had the experience of "one foot driving" but I'm sure I will get used to it. However, I do think the way my Prius works (regen on brake) is better from the "no surprises" perspective.

    I have a long downhill run (1.5 miles) to my house so I may well experience regen stopping.
     
  14. jimbakker666

    jimbakker666 Member

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    I was going to suggest the same thing. If you let the service center know I imagine they could pull the logs and figure it out. Even if it's something different than what's been mentioned, it would allow Tesla to get ahead of any *potential* issue. Not that it's an issue, but if it were I'm sure Tesla would want to know ahead of time so they could figure it out.
     
  15. brianman

    brianman Burrito Founder

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    So is non-brake-pedal braking a disadvantage to every manual transmission vehicle as well?
     
  16. ddenboer

    ddenboer MODEL X #1770

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    This happened to me about 5 months ago. I wrote about it here on the board, and haven't thought about it much since, as it only happened once.
    The ideas around it being caused by a bump might be likely, but in my case, I was on a relatively smooth section of hwy 101 when it happened.
    My advice is to stay alert for it happening again, and if it does, follow the advice of others and call it in.
     
  17. scaesare

    scaesare Active Member

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    Did it again last night.

    Given the suggestions folks here have made, I've been pretty attuned to what I'm doing, and it was not brake pedal or shift lever action.

    It also was what I believe was an average stretch of absolutely dry asphalt. I immediately glanced in my mirror, but it was dark, so not a lot to see.

    If it happens again, I'm going to turn around and examine the street surface if possible.

    Odd.
     
  18. EarlyAdopter

    EarlyAdopter Active Member

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    Contact Tesla service. Note the date and time it happened. They can pull the logs from the car and see if there's any event recorded around that point.
     
  19. stevezzzz

    stevezzzz R;SigS;P85D;SigX

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    No sense waiting for it to happen again: this is not normal behavior. Call it in.
     
  20. PhilBa

    PhilBa Active Member

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    No, It's different. In an a manual transmission ICE, when you fully let off the accelerator of an in gear car, it ALWAYS slows down. In the Tesla, same action ALMOST ALWAYS causes the car to slow down. It's the exception that I was pointing out. I fully believe your car's behavior should never surprise you.
     

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