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Why does regenerative braking not work well in the cold?

Discussion in 'Model 3' started by argon2018, Feb 11, 2019 at 6:20 PM.

  1. novox77

    novox77 1.21 Gigawatts

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    This is why if possible, you should schedule your charge closer to when you need the car. That way the residual heat from the charging process isn't lost to entropy and preserves your regen during your drive.

    I haven't quantified it, but this year, my electric usage is way lower than last year, and some of that might be because I've started to schedule charging to start 3 hours before my morning commute, as opposed to charging immediately when I get home.

    And anecdotally, with just 1 hour of charging, I have the full regen bar back. 30 min gets a lot of it back. this seems way better than relying on just a battery heater to condition the battery.
     
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  2. jerry33

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

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    If you've ever taken a look at Toyota's New Car Features manual where it describes the brake simulator, you'll quickly see why Tesla chose not to go down that path. Four pages of diagrams showing all the brake line, mechanical, and electrical connections--and it still doesn't give totally smooth braking in every circumstance.
     
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  3. ohmman

    ohmman Maximum Plaid Member

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    Definitely. I rarely have the need at home because of my moderate climate and garage, but when we go to Tahoe I always set up charging so that it's finishing up just as we're planning to leave.
     
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  4. ewoodrick

    ewoodrick Active Member

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    Totally agree!!!

    So many people seem to think that the purpose of regen braking is for braking. They seem to forget that regen braking is for the battery.

    Which means "So what if regen isn't working" the battery can't accept or doesn't need more charge. You may have to use the brake for stopping.
     
  5. Atari2600

    Atari2600 Member

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    Is it correct to assume the higher the charge rate the faster it heats up? So 48 amp charging FTW?
    I tried 30 amp for an hour before I left this morning but still had 1/3 of the dots.
     
  6. jerry33

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

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    Did you also do preheating for 30 minutes? Was range mode set off? I've found that you also need to do these.
     
  7. Atari2600

    Atari2600 Member

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    No to the preheating. Not sure what range mode is on the Model 3. It did kick several dots down, just wondering if 18 more amps would make a huge difference in an hour. Logic suggest yes since losses seem the same at any charge rate so double the charge rate should double the heat.

    Keep in mind I would rather keep the efficiency up as much as possible. I do preheat the cabin to 65F but normally I am in the car before it reaches 65F as I turn that on right before I am ready to head out.
     
  8. SageBrush

    SageBrush 2018: Drain the Sewer

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    I don't think so. The entropy change is small.

    I like the balloon metaphor more: air wants to come out a lot more than it wants to go in, and the stiffer the balloon the more this is true.
     
  9. jerry33

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

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    Try setting the preheating to HI. I've found that if you heat soak the cabin, you don't need to turn the heat on unless your commute is more than 25-30 miles one way. Don't know if there is range mode on the 3, mine is an S.
     
  10. ngogas

    ngogas Member

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    Can’t wait till they introduce capacitor to capture these energy for take off usages.
     

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