To regen or not regen?......that is the question.

Discussion in 'Hyundai Kona Electric' started by Dgercp, Aug 18, 2021.

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  1. hobbit

    hobbit Well-Known Member

    I didn't bother reinstalling the brake light telltale on the newer Kona, because I already pretty
    much knew what the story is with regen. The far more major concern is TO use the service
    brake pedal and make sure they come on when warranted by circumstance, e.g. someone
    behind me that needs to know I'm slowing. Playing games with regen level 1 or 2 just under
    the threshold when the lights come on, when someone who matters at the time is NOT likely
    to expect it, is the nadir of preventable stupid.

    _H*
     
    KiwiME likes this.
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  3. Tomek

    Tomek Active Member

    Hyundai set it up more or less like in the ICE - when you take your foot off the gas and brake using only the engine, the brake lights do not come on. I haven't checked this thoroughly, but it seems logical to assume that in BE taking your foot off the gas at a medium or high regen level should cause the lights to come on. It is difficult to establish a clear line, especially since the ICE lights will turn on even when you barely touch the brake pedal with your foot and the car will practically not slow down.
     
  4. Surlycat

    Surlycat Member

    Thanks for this prompt, Wildeyed. I did just that, and like you had a good read through of some interesting debate on regen & coasting. If anyone's interested, just pop "Regenerative Braking" in the search bar.

    What a great car, and kudos to you all doing the early work learning & teaching the rest of us now joining the EV ride!


    Sent from my iPhone using Inside EVs
     
  5. There are specifications to which the cars will be constructed.

    This is from https://unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/2018/R013hr4e.pdf
    UN Regulation No. 13-H

    Uniform provisions concerning the approval of passenger cars with regard to braking


    Screen Shot 2021-08-21 at 11.59.57.png
    I suppose the rate of deceleration will vary depending how loaded the car is, which would be why there is the "may be generated" band, so it wouldn't directly correspond to a particular regen level under all conditions.
     
    Last edited: Aug 20, 2021
  6. thank you for the info above,
    for me one very good reason to regen is on my last ICE car, i paid over $2,000 to have the pads and discs replaced.
    new i drive a 2022 Kona ev i do,not think i will ever have to do that again with regen in use. that's a big saving on my service costs.
     
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  8. Shark

    Shark Active Member

    I use regen as much as reasonably possible, and consider touching the brake pedal to be a "failure" as I've wasted energy :) Actually I've become quite proficient at stopping the car smoothly without touching the brakes.
     
  9. hobbit

    hobbit Well-Known Member

    You do realize, I hope, from numerous prior posts and articles on the subject, that using the
    brake pedal is anything but a "fail" because the Kona exclusively uses regen as much as possible
    before resorting to hydraulics, usually at the very end of a stoppjng event, right?

    Just be gentle on it, and it not only works like your paddles but is far more controllable.

    _H*
     
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  10. PRGDénia

    PRGDénia Member

    Has anyone checked what auto recuperation does to their efficiency. I found that activating that actually increased the km/kWh I was getting from my Kona.
     
    electriceddy likes this.
  11. Danhen

    Danhen Active Member

    I for one was not aware of this, perhaps because I'm relatively new to the forum. In the last few minutes I went back and looked at the OM, and I don't see where this is mentioned, at least not clearly. Can you provide links to the articles you mentioned? If I'm not fully understanding regen, I have to think others here are in the same boat and would benefit from reviewing the articles you mentioned. Thanks.
     
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  13. [​IMG]
     
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  14. Jimct

    Jimct Active Member

    I took a suggestion from someone on this forum by taping a piece of foil over the center brake light, making it easy to see even in daylight. I found the brake lights come on at some point between the 2nd and 3rd bar of the regen indicator. They also light up about a second after the regen paddle is applied.
     
    Toolworker likes this.
  15. hobbit

    hobbit Well-Known Member

    My original rant about exploring this is here, and the thing to especially note is the "downhill
    hot rotors" test. Even a small amount of hydraulic pressure would generate perceptible heat.
    Note how the lighter-gray area around "I" in the above chart doesn't enter the blended area;
    that's what I mean by "gentle", which implies good predictive driving. That still gives you over
    50 kW of recapturable slowing power with very little loss, and whether you get that with the
    paddles or the service brake it pretty much doesn't matter. Hyundai did a nice job on this, what
    I cynically call a "Prius-grade" bit of engineering since that was where I first observed strict
    avoidance of the hydraulics wherever possible.

    _H*
     
  16. To see when your brake light comes on, consider installing a temporary indicator using this technology, which I developed six years ago for my Volt:

    brakelightindicator.jpg
    Parts list:
    1. Aluminum foil
    2. Blue tape
    Use with caution, as it requires watching the rear view mirror. If I were going to try it today, I might add a viewer more in my line of sight by taping my pocketable camera to the dash and making use of its telephoto lens and 180 degree flip LCD.
     
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  17. I was surprised to learn a while back that GM's EV1 used this idea and perhaps was the first to do so. Here's a description:
    upload_2021-8-31_11-48-8.png

    upload_2021-8-31_11-48-42.png

    upload_2021-8-31_11-53-20.png
     
  18. Dgercp

    Dgercp New Member

    I logically think zero regen should optimize range over any preset regen. My little experiment did not confirm this, but it was just a little experiment of no real statistical strength. And, the advantage over preset regen I imagine is so small that ultimately you should just set the regen however you best like to.

    BUT, why is there any reason to use the paddles instead of the brake to slow the vehicle and regenerate power?? The paddle has less fine control, so is more jerky, and can not be used when turning, and it has no better regen efficiency ( i don't think) than the brake pedal.
     
  19. When travelling quickly on twisty hilly roads when it's constant acceleration and deceleration, I like regen level 3. Most of the time it is enough to slow down and occasionally is supplemented by the left paddle, usually before downhill corners. Very occasionally I need the foot brake for particularly tight bends, or if I've overcooked it :) But as you say it's personal preference, and a matter of driving custom rather than efficiency.
     
  20. None at all. Product differentiation and marketing, basically a sales gimmick.
    Noting the context is left-paddle-hold, I would have preferred that the accelerator pedal combined with the fixed levels 1-3 allowed you to come to a stop and hold position, what I understand is true one-pedal driving.
     
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  21. I always use regen level 3. It's the closest the Kona can come to one pedal driving, which IMO is one of the greatest and most underappreciated benefits of EVs. Driving an ICE car in stop and go traffic, you're constantly deciding which pedal to put your foot on and whether to brake or accelerate. Even if it's instinctive, it's tiring. One pedal eliminates that.
    +1.

    There were long discussions in the Volt forum when the paddle was introduced in the Gen 2 Volt. Some swore it gave more control. Some claimed it provided true one pedal driving, since you could use the paddle to stop without touching the brake. Hilarious! One pedal + one paddle, maybe.
     
    Ginginova, KiwiME and Dgercp like this.
  22. Hi!
    For information only: it is possible to block the left paddle, thus obtaining operation in e-pedal mode.

    Also: why e-pedal is not the default mode?
     
  23. Well, try it. I just did and it's a hoot but does slow things down a bit. Not sure what you mean by "e-pedal", no such named feature on the Kona, default or not.
     

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