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Regen Light

Discussion in 'Roadster' started by Tesla 940, Mar 1, 2013.

  1. Tesla 940

    Tesla 940 Member

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    This morning I charged in Standard Mode to 194 Ideal Miles (seems a little high) and started driving about 15 minutes later (still at 194 Ideal Miles). The car was in the garage and outside temp was in the 50s. The Regen Light was on - don't know if it was on from the very beginning but probably was - but Regen was working. Light stayed on for about 8 miles.

    Anyone else have this happen?
     
  2. roblab

    roblab Active Member

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    First off, What size is your battery? Second, What do you mean by "regen light"?

    I am assuming you have the 60 kWh battery, and I am assuming you mean the golden dashed line in the regen green area on the right lower side of your speedometer.

    I live on a hill. No matter when I charge (usually done before midnight) and leave (usually around 8 AM) the golden line appears between 60 and 15 kW of charge. Tesla has the regen set up so that high power regen won't heat up the battery when you try to charge it if it is nearly full already. It will allow low power regen, but limits it. Some here have also postulated that the battery has to heat up first, but I have "heated" my battery before driving (charging to Range Mode full, letting sit rest of night, cabin is warm from battery heat) and golden line is still there going down the hill. After a few miles the charge is down a bit and it will take more regen, until the line disappears altogether.

    I would guess that owners who live on the flat hardly ever notice that regen is being limited. It can be disconcerting if you are expecting a rapid slowdown and don't get it, but you still have *some* regen.
     
  3. Doug_G

    Doug_G Lead Moderator

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    @roblab, this is the Roadster section. He has a 53 kWh battery. The light he is talking about is the "NO regen" light, i.e. REGEN with an X through it.

    @Tesla940, I can't explain the light behaviour; in the conditions you describe it should not have been lit. Did you have full regen power or partial? The light turns on when regen is only partially limited (the Model S display is more informative).
     
  4. Zextraterrestrial

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    #4 Zextraterrestrial, Mar 1, 2013
    Last edited: Mar 1, 2013
    I get regen limiting (in the S) somewhere in the 45-50 degree temperature range and below if my car is cold and wasn't charging in the morning.

    ...oops yes, Roadster, sorry

    totally different battery mass/layout.
     
  5. Doug_G

    Doug_G Lead Moderator

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    @Zextraterrestrial, that is true for the Model S, but this is the Roadster section. I've never had the regen limit light come on in the Roadster unless the temperature was below freezing and the car had cold soaked.
     
  6. Tesla 940

    Tesla 940 Member

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    @Tesla940, I can't explain the light behaviour; in the conditions you describe it should not have been lit. Did you have full regen power or partial? The light turns on when regen is only partially limited (the Model S display is more informative).[/QUOTE]

    Thanks for the reply. The actual Regen seemed "normal" - I didn't know partial regen was even possible.

    I'll watch more closely in the future and post information about any future occurances. My annual service isn't due until June. I don't see any need, at this time, to have it "looked at" by TM until that time.
     
  7. strider

    strider Active Member

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    Hmm. Definitely odd. But to echo Doug, when regen is disabled due to a range charge (never had my car in freezing weather) the regen will start coming back as you burn miles but the light will stay on until some X% of regen is available and then it will switch off. That's the problem w/ a light vs the Model S display. It also works the other way in the morning if it's cool regen will be limited due to cold tires not having enough traction but the light won't come up. It just won't regen as far as it does when warm.
     
  8. vfx

    vfx Well-Known Member

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    I've seen this. Partial regen at first drive on standard charge. No light. Can't get anyone to believe me though.
     
  9. Botbldr45

    Botbldr45 Member

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    Had regen go out one day with the light on after 992 was sitting for eight hours in temps below 30 degree at work. No charging was going on. It took about 5min of driving and light went out and regen was back. Happened only one time this winter. Never had partial regen although maybe I have felt the car slowing on regen irregularly ..... At different rates once or twice...... I'll look for it. This stuff happens went temps are lower than the 50 degrees Tesla940 is talking about
     
  10. Doug_G

    Doug_G Lead Moderator

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    I've had no regen due to cold (and due to Range charge) many times in the Roadster. It always comes back gradually, so you can have some regen even while the No Regen light is lit.
     
  11. TEG

    TEG TMC Moderator

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    Someone told me that the no-regen light can sometimes come on if the 12V aux battery voltage is low too.
     
  12. Doug_G

    Doug_G Lead Moderator

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    That sounds plausible and bizarre all at once.
     
  13. Botbldr45

    Botbldr45 Member

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    Seems more bizarre than plausible ..... :)
     
  14. brianman

    brianman Burrito Founder

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    Totally makes sense to me, actually.
     
  15. strider

    strider Active Member

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    And conversely, you can have limited regen even while the No Regen light is NOT lit.
     
  16. speedy99

    speedy99 2.5 Roadster

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    I've had both, but only on a range mode charge. Normal charge for me is only about 187 miles, I wonder if you had range mode by accident, or a top off. Seems anything above 195 might trigger limited regen. I haven't looked closely to know exactly when regen fades or turns off. Probably a function of both the state of charge and battery conditions/temp.
     

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