Weird/dangerous ACC/regen braking behavior

Discussion in 'Hyundai Kona Electric' started by victor_2019, Aug 17, 2019.

  1. Esprit1st

    Esprit1st Well-Known Member

    That would make sense since we don't have a second motor in the back . Unless they come out with a dual motor option ...

    Sent from my moto x4 using Tapatalk
     
  2. XtsKonaTrooper

    XtsKonaTrooper Active Member

    Its because most of the ppl at the dealers or management, havent h true clue about the features . Its pretty well the engineers/designers and us, as the early adopters (EV Pioneers).
     
  3. Gjpzee

    Gjpzee Member

    Something similar happened to me today. I was on regen 2 or 3 while slowly turning around in a parking lot. Suddenly the regen went off and the car coasted ahead, I had to slam the brakes to stop the car. I tried to replicate it but was not able to.
     
  4. electriceddy

    electriceddy Well-Known Member

    I hope this does't develop into a new rash of problems, we have enough already! Keep us posted, BTW what was the 12V accessory battery voltage (if you have a meter)
     
  5. victor_2019

    victor_2019 Active Member

    I also have a Honda clarity

    now the honda clarity unfortunately doesn't have the strong regen capability of the kona and it uses blended braking all the time, but you can feel the difference in braking force when the regen braking is not possible.

    when applying the brake with a discharged battery there is a mix of regen and friction braking and you get a specific level of deceleration for a specific brake pedal pressure.

    however when the battery is fully charged, no regen is possible. at this point when pressing the brake pedal you only get friction brakes, and you can tell that for the same level of pedal force the braking of the car is a lot more sluggish.

    and this is exactly the sensation I felt when I pushed on the brake that day, for the same level of brake pedal force, with missing regen, the braking was a lot more sluggish than I was expecting. The only question is why the hell my regen disappeared momentarily.

    I tried to reproduce this with a fully charged battery but it seems the kona always allows some level of regen even with a "full" battery, unlike the clarity. (meaning the "100%" battery level on the kona probably has more margin than on the clarity and they don't disable regen immediately). So the braking was normal.
     
  6. Esprit1st

    Esprit1st Well-Known Member

    Are you sure you didn't touch the paddle accidentally?

    Sent from my moto x4 using Tapatalk
     
  7. Gjpzee

    Gjpzee Member

    I do not recall using the left paddle, but I use it frequently so it could be possible I sub consciously pressed it to slow the car.
     
  8. Gjpzee

    Gjpzee Member

    I have a multimeter but I charged the car overnight and drove a bit today so i guess it's too late. But just curious what could be the relationship between regen failing and the 12v battery? Wouldn't regen be using the main battery?
     
  9. electriceddy

    electriceddy Well-Known Member

    Just thinking software glitches, possible command issues to the brake cylinder hydraulics.
     
    Gjpzee likes this.
  10. Wildeyed

    Wildeyed Well-Known Member

     
  11. Wildeyed

    Wildeyed Well-Known Member

    Run the onboard diagnostics.
     
  12. Gjpzee

    Gjpzee Member

    Bluelink showed everything as normal. Can we run diagnostics from the car dash settings?
     
  13. Wildeyed

    Wildeyed Well-Known Member

    As far as I know the onboard diagnostics are accessed through the BL icon and is the same thing as the remote (phone based)BL diagnostics.
     
  14. nigels

    nigels Member

    OK, help me out here. Why would holding the left paddle not cause deceleration due to regeneration? I’ve experienced left paddle not slowing the car down and I’m trying to understand whether that’s normal or not. This post made me think I have my mental model of how the left paddle works wrong.
     
  15. victor_2019

    victor_2019 Active Member

    two reasons:

    1 - the battery is really full and regen not possible anymore. the dash should display a warning

    2 - there is a software glitch in the car's computer. my regen temporarily disappeared when I was pressing brake pedal, not the left steering wheel paddle.
     
  16. Gjpzee

    Gjpzee Member

    I wonder is there is a perfect storm of events that cause this to happen. I was at slow speed, maybe 5mph, on regen 2 or 3 and braking at the same time. What is don't remember is if I used the left paddle or not. I was shaken after the regen was lost and had to react reflexively by slamming the brakes which skidded the car to a stop.
     
  17. KonaTom

    KonaTom Active Member

    regen cuts off around 5mph. Many people have experienced this thinking the car surges ahead while braking, but it is just the regen cutting off and you need to press the brake to stop, or hold the left paddle to come to a stop. I wish the regen would continue right to a stop for true one pedal driving, without having to hold the left paddle.
     
    Gjpzee likes this.
  18. nigels

    nigels Member

    This makes sense. Thanks, @KonaTom. In my case, I was approaching a junction quite slowly while going down an incline. Auto regen was slowing the car, but not enough to stop me at the intersection, but when I pulled the left paddle to slow to a stop it felt as if I'd gone into neutral in a manual transmission car. The car accelerated towards the junction and I had to quickly brake. Given that the brake pedal integrates regen and friction braking so seamlessly, I'm not sure I'll bother with playing the will-it-stop-in-time guessing game with the left paddle now.
     
    electriceddy likes this.
  19. Gjpzee

    Gjpzee Member

    This makes sense, however I was not able to replicate it. I'll try and see if I can replicate it in an empty parking lot at a speed less than 5mph.
     
  20. JSU

    JSU New Member

    As I read all three pages of this conversation, I was wondering how the Kona's regen handles loss of traction. In my old i3, if the drive wheels (rear on the i3) lost traction even for a millisecond (like due to loose sand on the road, or some rough road surfaces), the regen would cut out 100%. Since in the i3, you can't shut off or vary the level the regen yourself, it had this safety feature to prevent wheel lockups. So i3 drivers are trained to always be ready to pounce on that friction brake if this type of situation occurs. I did need to slow down more quickly than I thought recently when my kona hit some rough road at an intersection where a car pulled out too early in front of me. I let off the accelerator expecting the initial slow down from the Kona's regen (set to 3) but it just wan't there, so I had to quickly apply the friction brakes. But I do believe I may had lost traction on that initial full off the pedal Level3 regen.

    Does anyone know if this feature of the regen cut off is something also found in the Kona electric? I'm sure I will find out when I can play in the snow once Winter comes.
     

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