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"Regen Limited" message on screen?

Discussion in 'Model 3' started by daniel, Mar 6, 2018.

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  1. daniel

    daniel Active Member

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    Every time I start my Model 3, I get a message on the screen telling me that regenerative braking is limited. When I'm actually driving, regen seems to work fine, though if my regen has been limited ever since I got the car I'd have nothing to compare it to. It's definitely less than on the Roadster, but I already knew it would be.

    My ambient and battery temperatures are not extreme. The battery is charged to somewhere around 80%. I have regen set to Normal.

    Nothing actually seems to be wrong, so I'm really wondering what's the deal with the message.
     
  2. Chewy3

    Chewy3 If MacGvyer had a beard

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  3. Msjulie

    Msjulie Member

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    It's been cold here (well for CA) and every morning I get that message with often lasts all the way to work. In the warmer afternoon, never.. and in truth it does seem to have a fair amount of regen anyway.
     
  4. daniel

    daniel Active Member

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    Surely, 40° F. should not be cold enough to limit regen???
     
  5. JonathanD

    JonathanD Member

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    To what % are you charging the battery?
     
  6. david_42

    david_42 Member

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    This is a limitation of the cold battery, not regen itself. The charge rate the battery can accept drops off rather quickly below 50F. It comes back as the battery warms, but your morning commute might not be enough to reach NOT.

    By the way, if you are an enthusiast of one-pedal driving, try not to be surprised when you suddenly don't have any braking on the accelerator.
     
  7. MP3Mike

    MP3Mike Well-Known Member

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    Yes, I think it is. (Or at least Tesla thinks it is.)
     
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  8. UrsS

    UrsS Member

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    According to the service rep that message comes on when the battery is at or below 50 degrees. And my observation of the same does confirm this. Actually a bummer for me, since my first few miles of driving are down the hill and I get a little bit, but not the full benefit of gravity generated electricity.
     
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  9. SageBrush

    SageBrush 2018: Drain the Sewer

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    Is 40F the night's nadir or your temperature when you take off in the AM ?
    Also, "limiting regen" does not tell us by how much. It might just be the lawyers at work
     
  10. Jason Bourne

    Jason Bourne Member

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    If you have your car plugged in over night, even if you've reached the charging limit set, the car will keep the battery warm enough to use full regen.
     
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  11. MP3Mike

    MP3Mike Well-Known Member

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    I have never heard that, or have seen anyone report that. In recent firmware/app updates Tesla has made it so that if you precondition your car it will heat the battery to reduce the impact to regen, but it won't heat the battery enough to enable full regen. (The best way to do that is to charge your battery just before leaving.)
     
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  12. daniel

    daniel Active Member

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    I don't know the percentage, but it reports a range of 220 miles when it's done charging. I guess that's about 66%. I might raise it a bit.

    Thank you for that information. I think it's crazy that they set the limit there. My Roadster didn't cancel regen until the temperature was well below zero. And it didn't feel as though it was limiting it until it quit entirely and the "regen" icon appeared on the screen.

    The car lives in the garage, where I doubt it's ever colder than 40° F. at this time of year. Yesterday I took it to the car wash, then parked in the sun while I dried it off. When I started the car again, I got the message. This morning I did not get the message when I started. I went to the recycling center where I was parked for a while as I unloaded my recycling and then talked to the worker there about some recycling stuff. When I started the car again, I had the message, and no regen until I'd been driving a short bit. It was a little over 30° F. outside.
     
  13. dragoljub

    dragoljub Member

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    I have the same issue. It’s hurting my Wh/Mile average I think. Little regen on downhill in mornings.
     
  14. jsmay311

    jsmay311 Member

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    That's my understanding too.

    Doesn't it have to do with Tesla using NCA battery chemistry (which is more sensitive to mildly cold temps) instead of the industry standard NMC?
     
  15. novox77

    novox77 1.21 Gigawatts

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    You cannot charge lithium ion right around freezing temps without damaging the battery. So if your car is cold soaked at 30 degrees overnight, expect to have no regen capability when you start driving. As you use the battery (discharging it), the battery will warm up and your regen ability will gradually appear.

    In my Model S, personal experience is that the battery needs to be around 45-50 degrees before I have full regen capability. In the S, you can see how much regen potential you have in the binnacle display; there is a yellow dotted line that shows you max regen.

    At 40 degrees, I only have 30kW max regen capability. Whereas when unlimited, it is 60kW+.
     
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  16. Doug_G

    Doug_G Lead Moderator

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    Yes, it is. The pack needs to be above 7C (about 45 F) to get full regen. You don't get zero regen until it is much colder, though.

    Also if you charge to 100% it will limit regen, to prevent overcharging the battery. Don't charge above 90% for routine usage; only use that for long road trips.
     
  17. SageBrush

    SageBrush 2018: Drain the Sewer

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    If NCA is a chemistry that likes the heat, it will a nice change for the better, even if it means some reduced power and regen at the beginning of a drive.
     
  18. daniel

    daniel Active Member

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    This part I knew, from the Roadster, and because it's obvious that you can't add more fuel to a full tank. I only ever charged the Roadster to full one time, when I was planning a longer drive. Having no regen really felt wrong, even though it then behaved just like the Zap Xebra that it replaced (though the Xebra had no creep either). (I still miss that little P.O.S. That was so much fun to drive.)
     
  19. Doug_G

    Doug_G Lead Moderator

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    Oh, right, I do recall that.

    It's interesting that you're getting a message with a minor limit. The current Model S firmware doesn't even show you anything about regen unless you deliberately put the power display on the center screen. (The original non-autopilot firmware showed this status at all times.) So if you aren't aware of it, you'll have no indication until you hit zero regen. Of course you'll notice that the car drives a bit differently...
     
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  20. jgs

    jgs Active Member

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    Actually, even if you don't have the power display on the binnacle, it'll pop it up for a few seconds when you power the car up if regen is limited, displaying a yellow warning triangle. But it goes away pretty quickly. It's not a very effective warning, but it does exist. It also tends to put up the warning triangle when the battery is almost but not quite warm enough to do full regen -- it flips back and forth between displaying the yellow dotted line, and not. Whenever it flips from no limit->limited, it displays the triangle for a few seconds. It's a little annoying, I think there used to be more hysteresis.
    Yeah, I still miss that.
     

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