Speak EV - Electric Car Forums banner
1 - 12 of 12 Posts

·
Registered
2020 Kona EV, Red, 230.4MJ (64kWh) Premium SE (10.5kW OBC)
Joined
·
82 Posts
Discussion Starter · #1 ·
I have noticed that when driving at a constant speed (both manually and when using the SCC), the KonaEV (2020MY) illuminates the brake lights (easily visible in the mirror at night, and often visible during the daytime too) for even the slightest downhill grade. In my opinion this is dangerous because the vehicle is not slowing down at all, however if there was a need to slow down suddenly, the vehicle behind would not be alerted by the brake lights going on because they are already on. I have seen this in all most regen levels, even regen-0 when using the SCC, but obviously not when driving "manually".

I have also noticed that when using the SCC and the speed limit reduces by 10mph, setting the new speed limit causes the vehicle to brake quite sharply, again illuminating the brake lights even in regen-0. My traditional/ICE vehicle with (non-smart) cruise control simply reduces the engine power output until the speed naturally reduced to the newly set limit, decelerating at a rate roughly equivalent to regen-1 on level ground in the KonaEV.

Finally, when using the speed limiter, holding a constant pedal position as the road begins to descend results in the speed slowly increasing. Surely the function of a speed limiter is to, um, limit the speed? We're not talking a steep descent - even the gentlest of downhill grades is enough to start the vehicle speed increasing, although obviously the steeper the descent, the faster the speed rises. My traditional/ICE vehicle with a speed limiter is able to hold a constant speed even on a moderately steep descent without me needing to move my foot at all, so why can't my (much newer) KonaEV?

Overall I find that the KonaEV drives down the road flashing the brake lights far more than any "normal" car would, irritating drivers behind and potentially hiding a genuine application of the brakes. Am I alone in finding this annoying and even moderately embarrassing?
 

·
Registered
Joined
·
201 Posts
This is a funny observation. People have been complaining that the Konas brake lights are not coming on when slowing down in the earlier MY. I guess Hyundai has overcompensated and now they turn on constantly?

I have noticed the brake lights coming on on my 2019 Kona when using SCC and it slows down even the tiniest amount. However not when driving manually.

Well, I guess you can't get everything right, Hyundai.
 

·
Registered
Joined
·
362 Posts
The brake lights will should come on when the car reaches a certain declaration force. So slowing on regen 1 might not activate the brake lights where levels 2 and three they will activate. As for coming on on downward gradients the brake lights coming on is a warning that the car is slowing which surely is a good thing. The following driver should always be alert to changing circumstances, if you were going downhill with your foot on the brake to prevent you breaking the speed limit your brake lights would be on and you braked harder to avoid something is the same principle.
If you are driving on SCC it is my understanding that the SCC is control of regen not the regen you had set previously.
The speed limiter is a difficult one I've not had it on previous cars, but in the Hyundai's it seems to prevent you speeding using the accelerator.
Your car does what it does so don't be embarrassed by it. Soon a greater number of cars will all be doing the same.
 

·
Registered
2020 Kona EV, Red, 230.4MJ (64kWh) Premium SE (10.5kW OBC)
Joined
·
82 Posts
Discussion Starter · #4 ·
The brake lights will should come on when the car reaches a certain declaration force.
I agree - the problem is that the brake lights come on when I am travelling at a constant speed, i.e. I am not decelerating at all, and there is no "deceleration force". According to addendum 12-H and regulation 13-H of the UN standard for vehicles (https://unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/R13hr2e.pdf), "the signal", i.e. the brake lights, should behave as defined in clause 5.2.22.4 quote here:

5.2.22.4: Electric regenerative braking systems as defined in paragraph 2.17., which produce a retarding force upon release of the accelerator control, shall generate the signal mentioned above according to the following provisions:
Vehicle decelerationsSignal generation
≤ 0.7 m/s²
The signal shall not be generated
> 0.7 m/s² and ≤ 1.3 m/s²
The signal may be generated
> 1.3 m/s²
The signal shall be generated
In all cases the signal shall be de-activated at the latest when the deceleration has fallen below 0.7 m/s²

Since the units used are a little unusual for many people, a constant 0.7m/s² is equivalent to slowing to a walking pace (4mph) from 30mph in about 16 seconds, whilst at 1.3m/s² it would take about 9 seconds. My ICE will do more than 0.7m/s² just from relaxing the gas pedal slightly without even changing gear - but the brake lights don't come on.

If I am driving at a constant speed, the vehicle deceleration is 0.0ms², therefore the regulation requires that the brake lights ("the signal") shall not be lit ("generated"). My KonaEV is not behaving in accordance with this regulation.

As for coming on on downward gradients the brake lights coming on is a warning that the car is slowing which surely is a good thing. The following driver should always be alert to changing circumstances, if you were going downhill with your foot on the brake to prevent you breaking the speed limit your brake lights would be on and you braked harder to avoid something is the same principle.
Again, I agree that the car is behaving like a poor driver who rides the brakes all the way down a hill - but not like a good driver who has anticipated the hill and selected the correct gear to ensure that they have full control of the car - and yes, my ICE is an auto, and you can still descend even quite steep hills without riding the brakes in an auto. Riding the brakes is regarded as dangerous for several reasons, not least the fact that the brake lights are on when you are travelling at a constant speed.

The speed limiter is a difficult one I've not had it on previous cars, but in the Hyundai's it seems to prevent you speeding using the accelerator.
On my other cars, it prevents you speeding unless, as above, you are descending a steep hill in the wrong gear with insufficient "engine braking". My KonaEV accelerates even on the gentlest of downward grades.

Your car does what it does so don't be embarrassed by it. Soon a greater number of cars will all be doing the same.
Hmmm - I'm not sure that "soon all cars will make drivers look like they're driving unsafely" is a good enough reason for me to look like a numpty right now, and it certainly won't prevent the road rage incidents.
 

·
Registered
Joined
·
201 Posts
My ICE will do more than 0.7m/s² just from relaxing the gas pedal slightly without even changing gear - but the brake lights don't come on.
Which makes sense because your ice car doesn't even know you're braking if you're engine braking.

You can't compare that.
 

·
Registered
Kona64
Joined
·
1,771 Posts
S'good point tho, back a few years if I went downhill in a low gear at roughly constant speed, or slightly decreasing, no brake lights, as no pressure on that pedal

nowadays, and I think PHEVs too in a BMode, then with BEVs any use of "simulated engine breaking" causes the brake lights to come on
So riding the brakes without intending it compared with what I would have done a few years back

likewise at traffic lights, into neutral (or first being pre ready clutch still in) and handbrake on --- no brake lights
theses days in my Kona - lights on I think in either auto hold or foot on the pedal
 
  • Like
Reactions: esprit1st

·
Registered
EU base model with heat pump Sept '18
Joined
·
582 Posts
In the early days of the Kona EV there were a few rear-enders reported on Facebook. I can't help but think that was due to use of the left-paddle where the brake light extinguished once stopped before being fixed with the 196 update.
 

·
Registered
Kia Soul EV 2020
Joined
·
2,764 Posts
Brake light system was checked and no "faults" found, but anomalous brake light performance confirmed, so report sent to Hyundai requesting a fix is developed.
Just out of curiosity, how was it confirmed?
 

·
Registered
2020 Kona EV, Red, 230.4MJ (64kWh) Premium SE (10.5kW OBC)
Joined
·
82 Posts
Discussion Starter · #12 ·
Just out of curiosity, how was it confirmed?
I don't know for sure, but according to BlueLink their test drive included a blast at 70mph, so I imagine they had a second test drive in convoy watching the brake lights.
 
1 - 12 of 12 Posts
Top