MUST SEE video, especially for i-Pedal users

2280 Views 37 Replies 21 Participants Last post by sammyz, 1 d ago

AndersT2

Discussion Starter · 7 d ago

This can be both dangerous and as he mentions a little into the video, a reason both for fault in accidents and fines from the Police.

EDIT: For those who don't want to see, the quick breakdown. In i-Pedal the break lights don't come on before letting go of the accelerator pedal fully, or the care is at a full stop. With the different regen modes, it also have to fully let go of the accelerator pedal.

The cars behind will not see you breaking much of the time, if you don't use the breakpedal.

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adamsharif

· #2 · 7 d ago

AndersT2 said:
This can be both dangerous and as he mentions a little into the video, a reason both for fault in accidents and fines from the Police.

EDIT: For those who don't want to see, the quick breakdown. In i-Pedal the break lights don't come on before letting go of the accelerator pedal fully, or the care is at a full stop. With the different regen modes, it also have to fully let go of the accelerator pedal.

The cars behind will not see you breaking much of the time, if you don't use the breakpedal.

I think this happens in other modes too, including auto regen mode - but honestly, these people who rely purely on brake lights to know to slow down are a liability imo, personally I've sat behind Tesla's and other EVs that are clearly slowing down and no brake lights and it's never caused me an issue or any annoyance. I wonder if these accidents are also in part due to people driving too close behind another car that happens to be slowing down.

Yes, maybe the algorithm needs to be tweaked (I believe the deceleration if hits a certain gforce will trigger the lights) but also people need to pay attention to cars in front of them and not rely on brake lights so much.
With my previous ICE cars I often used engine braking to slow down and brake lights wouldn't have shown (sometimes with significant deceleration) and I never had any issues.

Reactions: 5

Tell It Right

· #3 · 7 d ago

adamsharif said:
I think this happens in other modes too, including auto regen mode - but honestly, these people who rely purely on brake lights to know to slow down are a liability imo, personally I've sat behind Tesla's and other EVs that are clearly slowing down and no brake lights and it's never caused me an issue or any annoyance. I wonder if these accidents are also in part due to people driving too close behind another car that happens to be slowing down.

Yes, maybe the algorithm needs to be tweaked (I believe the deceleration if hits a certain gforce will trigger the lights) but also people need to pay attention to cars in front of them and not rely on brake lights so much.
With my previous ICE cars I often used engine braking to slow down and brake lights wouldn't have shown (sometimes with significant deceleration) and I never had any issues.

2022 US Limited RWD owner here.

This is one of the main reasons I usually keep my regen at Level 1 and use the brake pedal for decelerating, which always turns on the brake lights. IIRC, the brake pedal will use regen to slow down if the regen is set to anything but Level 0. Of course, if you press the brake pedal hard enough (wanting to slow down faster than the regen can) it'll use the brake pads. So setting regen to Level 1 and using the brake pedal gives you the best of both worlds: brake lights to alert the people behind you, and regen braking to charge the battery and save on brake pad use.

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adamsharif

· #4 · 7 d ago

Over here I've been using auto regen level 3 for about a year, the only thing I do though which maybe makes a difference is if I need to slow down considerably I pull the left paddle for brief maximum regen and from what I've seen, the paddle always seems to trigger her brake lights.
I used to use i-pedal but stopped because actually it seemed to be less efficient than auto regen.

Regardless, I've never had any adverse reaction from a driver behind me when decelerating in this mode with my foot at least partially on the accelerator - or maybe I just haven't noticed it yet 😆

At the same time I do agree though that Hyundai's configuration for when the brake lights doesn't seem very good and could do with tweaking. That said I have a feeling this is probably similar with other manufacturers too.

Reactions: 3

HKtech

· #5 · 7 d ago

AndersT2 said:
This can be both dangerous and as he mentions a little into the video, a reason both for fault in accidents and fines from the Police.

EDIT: For those who don't want to see, the quick breakdown. In i-Pedal the break lights don't come on before letting go of the accelerator pedal fully, or the care is at a full stop. With the different regen modes, it also have to fully let go of the accelerator pedal.

The cars behind will not see you breaking much of the time, if you don't use the breakpedal.

This is not the problem....vehicles with manual transmission do the same thing..... if someone is following too close it his responsibility to react not only by watching brake lights but also observing how much distance is between.

Reactions: 5

TRT

· #6 · 7 d ago

HKtech said:
This is not the problem....vehicles with manual transmission do the same thing..... if someone is following too close it his responsibility to react not only by watching brake lights but also observing how much distance is between.

Yeah, but only if you set regen level to simulate manual transmission (ie, level 1). Regen levels greater than level 1 do not. Unless you are simulating changing down from 4th to second gear when you meant to change to third.

And I admire the trust you place in other drivers to stop when they can’t see brake lights. Drivers in your country are obviously far better than in mine.

Reactions: 1

DocinNC

· #7 · 7 d ago

HKtech said:
This is not the problem....vehicles with manual transmission do the same thing..... if someone is following too close it his responsibility to react not only by watching brake lights but also observing how much distance is between.

Ageed. This is what happened with a manual transmission for a century No brake lights when you downshift unless you press on the bakepedal. No one said the bake lights didn’t work then. The Ioniq 5 setup is actually better because the brake lights come on just by removing your foot from the accelerator, something that didn’t happen with manual transmissions.

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BigNerd

· #8 · 7 d ago

Our Y brake lights on regen and I think the Leaf does too.

I do think it's important one pedal driving does this.

Reactions: 1

Pontanius Black

· #9 · 7 d ago

While driving at night with auto-regen, I've noticed brake lights activate at what equates to about regen 2.

I think this is fine.

I've seen and driven ICE cars capable of stronger engine braking than this.

Reactions: 2

HKtech

· #10 · 7 d ago

Pontanius Black said:
While driving at night with auto-regen, I've noticed brake lights activate at what equates to about regen 2.

I think this is fine.

I've seen and driven ICE cars capable of stronger engine braking than this.

Brake light is active when deceleration threshold is reached...irrelevant to the regen number.

Reactions: 2

Pontanius Black

· #11 · 7 d ago

HKtech said:
Brake light is active when deceleration threshold is reached...irrelevant to the regen number.

As i would expect. I just mentioned that this is when it seems to meet the requirements for activation.

I think the video makes some valid points.
Only thing I really wanna touch on is this:

If you think 0.25 - 0.3 G is ‘rapid decelleration’ and you have stuff moving around the cabin, then you are driving in a dangerous environment and really need to fix that at once.
The car should be able to reach around 0.8 G (or more) at max decelleration on dry roads at fair temps. So about 3 times what he measured.

I mean, you should be able to reach about 0.1 to 0.2 G on icy roads with proper tires.

Personally, I’ve never been braking on snowy or icy roads and thinking, “Geee. This is some prime stopping power.”

And regen braking is much the same. It makes for a measured, relaxed drive.

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kuskye25

· #12 · 7 d ago (Edited)

The theory here is sound but that is where it ends.

I came to work this morning and it was pitch black out so I could see my hatch brake light. If I lift off the pedal all together in i-pedal mode, my brake lights come on and the vehicle stops mildly aggressively but still not as aggressively as when I actually brake. And this was his findings in the video.

Where I disagree is what point the light engages as you let the pedal out - and how much brake forces are being apply before the brake light comes on.

My foot was probably 80% out of the pedal when the brake lights turn on, if I push the pedal down just a slight bit more to where the brake light just barely is not on and hold it there i.e. "max breaking with no brake lights", sorry it's not braking any harder than when I downshift a manual trans on my old Mustang v8 to slow my speed.

Honestly at the point right before the brake lights turn on in i-pedal mode my old Mustang slows harder in a downshift. Once the pedal is out far enough to engage the brake lights, or you are completely off the pedal again it's still not as aggressive as me actually braking and at this point my brake lights are on, wonderful.

Overall sound theory but real-world testing for me disproves this being any kind of a danger on the Ioniq 5. I don't know about other cars, but on this car I strongly disagree. I think the manufacture did a fine job on this.

The only way I can get items to move around in the cabin from i-pedal is if im deep in the throttle and let off the throttle pedal all the way instantly, but again my lights turn on when i do that.

I urge everyone to drive at night, look at your hatch taillight. Let out your pedal to the max amount just before the lights engage and hold it CONSTANT there. Feel the braking, it's not much!!!

THEY DO WORK RIGHT, LOL!!

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kuskye25

· #13 · 7 d ago

AndersT2 said:
This can be both dangerous and as he mentions a little into the video, a reason both for fault in accidents and fines from the Police.

EDIT: For those who don't want to see, the quick breakdown. In i-Pedal the break lights don't come on before letting go of the accelerator pedal fully, or the care is at a full stop. With the different regen modes, it also have to fully let go of the accelerator pedal.

The cars behind will not see you breaking much of the time, if you don't use the breakpedal.

This is incorrect, my lights come on before i let off. I have the latest update and just got my car "2022 Ioniq 5 SE". Maybe they fixed it I don't know. But this is not true with my car. Mine come on when i left off the pedal to about 80% "or 20% throttle", and if you hold it at 79% "or 21% throttle" when there is no lights at all the vehicle is not braking that hard. As stated downshifting a gasoline car pulls as hard or harder with no brakes lights turning on.

Reactions: 3

DocinNC

· #14 · 6 d ago

kuskye25 said:
…sorry it's not braking any harder than when I downshift a manual trans on my Mustang v8 to slow my speed.

Honestly at the point right before the brake lights turn on in i-pedal mode my Mustang slows harder in a downshift. Once the pedal is out far enough to engage the brake lights, or you are completely off the pedal again it's still not as aggressive as me actually braking and at this point my brake lights are on, wonderful.

Overall sound theory but real-world testing for me disproves this being any kind of a danger on the Ioniq 5. I don't know about other cars, but on this car I strongly disagree. I think the manufacture did a fine job on this.

EXACTLY! This is a lot of hooha about nothing.

Reactions: 1

bl4C

· #15 · 4 d ago

This is an interesting topic raised in the video, specially because there are already 3 posts about it here

(I reply in this one, because it seems to have the most 'data' already).
Would be nice to have some real/official info on the intended behavior of the brake lights with using regen to slow down the car ... maybe the behavior is different depending on region or local regulations ?

kuskye25 said:
This is incorrect, my lights come on before i let off. I have the latest update and just got my car "2022 Ioniq 5 SE". Maybe they fixed it I don't know. But this is not true with my car. Mine come on when i left off the pedal to about 80% "or 20% throttle", and if you hold it at 79% "or 21% throttle" when there is no lights at all the vehicle is not braking that hard. As stated downshifting a gasoline car pulls as hard or harder with no brakes lights turning on.

Thanks for reporting this, you gave me an idea:

It would be great to have some test data from users ... a simple test just to check when the brake lights turn on (I can't test it myself yet, just 2 more months let's hope):

when driving at night, the brake lights should be visible on the main screen when this is set to rearview camera
pick a section of a road and your preferred driving speed, and choose a specific point to start the test (like a lamp post or something)
drive in i-pedal > at the test starting point, completely let go of the pedal > check if brake lights are active (they should)> remember how far you got when the car came at a full stop, this will be your reference distance
drive the same section again in i-pedal > at the test starting point, don't remove your foot from the pedal, but keep it at let's say 95% > check if brake lights are active (if they were not active at all, then you can stop the test)> now you should reach full stop a little further away than your reference point, but not by much (in case you are much further, you can try to press even less on the pedal)
as long as the brake lights became active, you could do another test with more pressure on the pedal (95-90-85-80-...)
if you want to go further in detail, you could check the maximum distance or time (from the starting point to full stop) you have been able to go while you had brake lights turning on ... by knowing the starting speed and the distance/time to full stop, the deceleration value can be calculated.

Let's take the example of the creator of the video:

Imperial:
He was driving at 60miles/h and it took 13s to full stop, this means about 0.2g and a deceleration of 7feet/s², resulting in a total distance of about 600-640 feet.
Metric:
He was driving at 95km/h and it took 13s to full stop, this means about 0.2g and a deceleration of 2m/s², resulting in a total distance of about 180-190m.

HKtech said:
Brake light is active when deceleration threshold is reached...irrelevant to the regen number.

Do you know what the deceleration threshold could be ?

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garsh

· #16 · 4 d ago

kuskye25 said:
Where I disagree is what point the light engages as you let the pedal out - and how much brake forces are being apply before the brake light comes on.

My foot was probably 80% out of the pedal when the brake lights turn on...

I just tested this, and I think I disagree with this characterization. Or possibly my vehicle behaves differently.

I noticed that the brake light didn't come on until the accelerator was almost all of the way out. I guess I could see it being characterized as 80% of the way. However, the remaining accelerator travel was just "dead space" - letting it go the rest of the way out didn't result in additional regen. So I could also see it being characterized as being completely released.

kuskye25

· #17 · 4 d ago

garsh said:
I just tested this, and I think I disagree with this characterization. Or possibly my vehicle behaves differently.

I noticed that the brake light didn't come on until the accelerator was almost all of the way out. I guess I could see it being characterized as 80% of the way. However, the remaining accelerator travel was just "dead space" - letting it go the rest of the way out didn't result in additional regen. So I could also see it being characterized as being completely released.

While I do agree that the last bit of pedal isnt much. The key factor for me is hold the accelerator down far enough to where the tail light doesn't come on. And hold it constant, feel the braking capability. Its not much. For me it's only mildly aggressive braking when I let the pedal all the way out. If I'm into the pedal at all "enough to where the tail lights are not on" The braking isn't that much even in i-pedal mode. This is the part for me that real world testing debunks all this hype.

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bl4C

· #18 · 3 d ago

At the end of the video, some deceleration values are mentioned for the EU, and they also appear here at the end of this article:
The Hyundai Ioniq 5 Needs To Rethink Its Brake Lights Before It Causes An Accident (slashgear.com)

So when taking this deceleration value of 1.3 m/s² (4.27 ft/s²) as brake light threshold, testing becomes more easy:
Drive in i-pedal mode at your preferred speed, slow down to 0, and check your distance or time ...

If slowing down more than 1.3 m/s², the brake light should be active.
The value of 0.7 m/s² (2.30 ft/s²) is also mentioned as a value from where brake lights should not be active anymore.

Would be great if anyone could check this in some real world testing

Metric example:
If you are driving at 70 km/h, and you slow down to 0 in less than 155 m or 15 s, the brake lights should have been ON.
If you are driving at 70 km/h, and you slow down to 0 in more than 280 m or 29 s, the brake lights should have been OFF.

speed	1.3m/s²	1.3m/s²			0.7m/s²	0.7m/s²
	distance	time	< if less than	if more than>	distance	time
90 km/h	250 m	19 s	< brake lights ON	brake lights OFF >	460 m	36 s
70 km/h	155 m	15 s	< brake lights ON	brake lights OFF >	280 m	29 s
50 km/h	70 m	12 s	< brake lights ON	brake lights OFF >	145 m	21 s
30 km/h	30 m	7 s	< brake lights ON	brake lights OFF >	55 m	13 s

Imperial example:
If you are driving at 45 mph, and you slow down to 0 in less than 545 ft or 15 s, the brake lights should have been ON.
If you are driving at 45 mph, and you slow down to 0 in more than 980 ft or 30 s, the brake lights should have been OFF.

speed	4.27ft/s²	4.27f/s²			2.30ft/s²	2.30ft/s²
	distance	time	< if less than	if more than>	distance	time
60 mph	950 ft	21 s	< brake lights ON	brake lights OFF >	1730 ft	38 s
45 mph	545ft	15 s	< brake lights ON	brake lights OFF >	980 ft	30 s
30 mph	250 ft	11 s	< brake lights ON	brake lights OFF >	445 ft	20 s
20 mph	115 ft	8 s	< brake lights ON	brake lights OFF >	200 ft	14 s

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SoCalStinger

· #19 · 3 d ago

Something I think is interesting is that our I-5 behaves this way, Our GV60 does not. The Brake lamps illuminate when you decelerate, as the I-5 should do.

Reactions: 1

Skyhawk828

· #20 · 3 d ago

kuskye25 said:
While I do agree that the last bit of pedal isnt much. The key factor for me is hold the accelerator down far enough to where the tail light doesn't come on. And hold it constant, feel the braking capability. Its not much. For me it's only mildly aggressive braking when I let the pedal all the way out. If I'm into the pedal at all "enough to where the tail lights are not on" The braking isn't that much even in i-pedal mode. This is the part for me that real world testing debunks all this hype.

We use regen level-3 on our car. I just took our car out tonight and drove it like we normally drive. The brake lights come on when the car decelerates under regen braking - even if my foot is still on the accelerator, if the car is regen braking the brake lights come on. Our car is a 2023 Limited. Can I "force" the brake lights to not come on when decelerating? Only if I barely decelerate... but it was no different than our ICE car decelerating when I take my foot off of the accelerator (no regen but just letting the car coast down a bit).

This is a total non-issue for our car. The brake lights work fine when regen is braking our car.

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