regen braking and icy roads

Discussion in 'Hyundai Kona Electric' started by Jgood, Nov 9, 2019.

  1. Jgood

    Jgood Member

    Having grown up in upstate NY I learned to drive in snow and am very familiar with the nuance of behaviors that cars present in the range of conditions from dry flakes/wet clumps/ice fog/freezing rain/blizzards, etc. One of the concerns I had about getting a Kona (or any car with regen braking) is how it affects a cars stability on iced roads. For example...driving in heavy traffic and icy conditions often requires abrupt responses to avoid someone else who's lost control in front of you. If I let off the accelerator pedal rapidly is the regen braking going to put me into a similar spin? Do people adjust the level of regen to lower settings when it gets slippery to avoid wheel slip? Has anyone had experience with regen braking causing problems like this or is it a non-issue? Just curious since the temps are now getting below 20°F and snow is predicted next week.
  2. First off: I don't have experience with this since I don't drive my Kona in icy conditions. I live in Nevada.
    However I am looking at it from a technical standpoint and I might be wrong about things.

    I believe that it is technically impossible to do separate tire beaking (ABS) with Regen. Regen can only be used to slow down a complete axle, not a wheel since we don't have in-wheel- motors. In that case it could be possible.

    So to use ABS and brake every wheel separate one has to use friction brakes.

    I don't know if the cars system is able to predict that by measuring outside temps. So there probably could be a weird braking switch from Regen to sudden friction braking.

    Sent from my moto x4 using Tapatalk
  3. This is something I am waiting to see, too. Where I live, we have a big hill to go down, and gets very slippery during black ice conditions in the winter. In the past, my ICE cars had their ABS working (you can hear it) all the way down, and often had to keep close to the right where at least one side wheels would get some grip. To be safe I am going to change my regen from 3 to 1 until I test it and get a good feeling for how it works. We don't get these conditions too often, so will probably have to wait a while, but am sure will see it sometime this winter.
  4. Kitsilano

    Kitsilano Active Member

    Here is a situation where I wish I had an electric car with rear wheel drive.
    R P likes this.
  5. Yes, at least with RWD you don't lose steering control when your front wheels are slipping.

    Having said that, have to wait and see. I am not convinced that ABS (on front wheels) won't work with regen.
  6. It never caused any issues for me last winter. Regen is actually very smooth and gentle, nothing that would ever trigger a slide. I would venture that Regen feathers the brakes more subtly than most humans.
  7. We had our first dumping of snow (over 20cm) a couple of nights ago in southern Ontario, and on my way home from work I approached a snow covered intersection. I have my regen at 1 and I use the brake pedal instead of the paddles, and the ABS DEFINITELY kicked in at the intersection. I can't honestly remember what it felt like going from regen to ABS, which I guess is a good thing. If it was more dramatic, I probably would remember that. I'll pay closer attention in future! In any case, ABS does work with regen.
    electriceddy likes this.
  8. But did the ABS work without pedal braking, ie regen only? 1 is pretty light regen, you need to try it with 2 or 3.
    Kitsilano likes this.
  9. That I didn't test. More snow is forecast this week, so I'll try and find a safe area to test that.
  10. I had ABS kick in this morning when I was using the regen paddle and no brakes. The ABS sensor apparently is functioning whether you are using the friction brakes or regen and will engage ABS when it senses wheel lock. My reaction was interesting. I let go of the regen paddle and hit the brake pedal and of course ABS continued. It was a very short episode, just a few feet and maybe a second or two.
    NP27, eastpole and R P like this.
  11. That makes sense, and what I wanted to confirm. Good news...
  12. Kitsilano

    Kitsilano Active Member

    ABS is the greatest safety feature of the modern car; it allows steering through a turn with the brakes full on. So glad to hear it works when regen is strong enough to initiate a skid.
    electriceddy and R P like this.
  13. That's interesting. We had more snow yesterday and I was testing this too. I could not get the ABS to kick in using only the paddles. I guess the regen did well enough without locking the wheels. The ABS did kick in when I used the brake pedal though - likely because I was applying more pressure than the regen would have. It's good to know it will work either way, under the right circumstances.
  14. I have to correct this. I have tried this again and ABS did not kick in. I think what I felt that first time was the locked wheels skidding on the ice. So please, do not hold down the paddle and expect ABS to function, use the brake.
  15. If ABS kicks in, you should hear it, sort of like a stutter/rattle. We still haven't had any ice or snow here for me to try it. But there is a big hill here where I live, just waiting for me...
  16. I tried holding down the left regen paddle on an icy downhill last week, and in my case at least there was *no* ABS - the tires lost grip and the car just slid. When I let go and used the brake pedal, the ABS kicked in.
    milesian likes this.
  17. GPM432

    GPM432 Active Member

    how did the car skid were the brakes applied or were you in regen
  18. hobbit

    hobbit Active Member

    If you want to investigate the differences between regen/blended stopping and
    pure wheel brakes alone, remember that Neutral disables regen entirely, including
    what comes from pressing the brake pedal.

  19. As far as I know, pulling back on the left paddle uses only regen and no brakes. That's when the car skidded. When I let go of the paddle and pressed down hard on the brake pedal, I felt the ABS acting to stop without skidding.
  20. GPM432

    GPM432 Active Member

    That's what I thought and I also thought regen would be good when going down an icy hill

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