Drivers who lift off the accelerator - 1pedal EV annoyance
Drivers who lift off the accelerator - 1pedal EV annoyance
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Discussion

arfur

Original Poster:

4,016 posts

244 months

Sunday 13th November 2022
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You know those drivers, especially on dual carriageways or on the motorway - forever lifting off the accelerator

With the advent of 1 pedal driving this becomes a real annoyance - the bl00dy brake lights

I've followed a couple recently in the dark on the A45 at 50-60 speeds and the constant, every 2-3 seconds of the brake lights coming on is something of a distraction. At this rate night time driving will be more akin of a flashing xmas tree.

Not a rant - just a recent observation

768

20,773 posts

126 months

Sunday 13th November 2022
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I thought the point of one pedal driving was to not touch the brake?

Dashnine

1,715 posts

80 months

Sunday 13th November 2022
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It’s certainly something I only became aware of recently, my hybrid does the same embarrassingly when regenerating and now explains why I’ve been ranting for a couple of years at people seemingly on and off the brake pedal all the time.

Apparently certain rates of deceleration at varying speeds require the brake lights to come on regardless of where your foot is anywhere near the brake pedal.

DMZ

2,115 posts

190 months

Sunday 13th November 2022
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Yeah adaptive cruise is a sure fire way to constantly accelerate and decelerate but I’ve seen plenty of Christmas light examples of EVs failing to coast as well.

delta0

2,552 posts

136 months

Sunday 13th November 2022
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They aren’t slowing down for no reason. Either keeping space with the car in front, change in speed limit or an obstacle.

arfur

Original Poster:

4,016 posts

244 months

Sunday 13th November 2022
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delta0 said:
They aren’t slowing down for no reason. Either keeping space with the car in front or an obstacle.
My point was relating to drivers who are constantly lifting off for no reason at all. You know - the ones where being a passenger is uncomfortable.

donkmeister

13,048 posts

130 months

Sunday 13th November 2022
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I've noticed the active cruise on my car (not an ev) can be quite "sales reppy" with its use of accelerator and brake, especially if someone has nipped into my braking distance gap. So, a situation where I would have lifted off or cancelled old-fashioned cruise control and just got a bit closer for a sec, ends up in hardish braking to keep the distance.

It makes sense because active cruise is only looking at the car in front (and possibly either side), it's not looking further up the road to see if you will need to stop soon.

donkmeister

13,048 posts

130 months

Sunday 13th November 2022
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F20CN16 said:
They don’t coast usually (unless there is an EV that allows you to select no regenerative braking). If you want to actually coast (at least in mine) you have to keep the accelerator depressed a little to cut out the regen.

It’s a new way of driving an EV vs ICE, where in an ICE you might lift completely off the pedal to coast, as above with an EV people are going to have to learn that they need to keep a little “throttle” on to coast. Though I suppose that’s like knocking an ICE into neutral. But then the brakes lights don’t illuminate when engine braking in an ICE.
From your username I'm assuming you have (or had) an S2000, which in my experience has a lot of engine braking available at motorway speeds - how do you find EV regen compares to that?

Smint

3,658 posts

65 months

Sunday 13th November 2022
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Ah that might answer something i've been seeing more and more of, that is cars that don't appear to be changing their cruise speed but the brake lights keep coming on every few seconds, wouldn't be so bad except for the lights being max level bright for no change in speed.

Don't like it, brake lights should mean deceleration of a certain rate or above has been triggered, or you get the situation of the boy crying 'wolf', when they really are important people don't register to the same degree.

Dashnine

1,715 posts

80 months

Sunday 13th November 2022
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Smint said:
Don't like it, brake lights should mean deceleration of a certain rate or above has been triggered, or you get the situation of the boy crying 'wolf', when they really are important people don't register to the same degree.
It is triggered above a certain rate of deceleration, the problem is that the rate is probably lower than you’d wish:

Vehicle decelerations Signal 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

1.3 m/s² is 2.9 mph/sec or 4.7kph/sec deceleration.

delta0

2,552 posts

136 months

Sunday 13th November 2022
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Smint said:
Ah that might answer something i've been seeing more and more of, that is cars that don't appear to be changing their cruise speed but the brake lights keep coming on every few seconds, wouldn't be so bad except for the lights being max level bright for no change in speed.

Don't like it, brake lights should mean deceleration of a certain rate or above has been triggered, or you get the situation of the boy crying 'wolf', when they really are important people don't register to the same degree.
They trigger at 0.7 m/s^2 which is just shy of 0.1 g deceleration. That’s a legal requirement at 1.3 m/s^2 just over 0.1 g.



Pistonpants

277 posts

117 months

Sunday 13th November 2022
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Best to turn regen off if you can. If you are a smooth driver coasting is more economical

Pit Pony

11,440 posts

151 months

Sunday 13th November 2022
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Maybe EVs need amber lights too.

Because I am old and wise, I drive my ICE car in such a way, that I rarely need to brake.

On the motorway, my anticipation levels allow me to click.the cruise control, a couple of mph lower or quicker, and maintain a safe distance.

The last time I was a passenger with my mother (in about 1990, she only had 2 positions for her left foot. Full on the accelerator, or full on the brake.

Now that's a scary ride.

Dashnine

1,715 posts

80 months

Sunday 13th November 2022
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Pistonpants said:
Best to turn regen off if you can. If you are a smooth driver coasting is more economical
Not convinced about that, certainly in my hybrid quite a bit of battery charge is regained by regen instead of braking, especially on a steeper hills.

Zero Fuchs

2,749 posts

48 months

Sunday 13th November 2022
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I can't say I've really noticed this when following other EV's and I've followed plenty. Certainly nothing like a Christmas tree.

My i3 has permanent regen and I never really use cruise but have learnt to use the pedal, which is fairly heavy compared to an ICE car. I admit that it can seem like you're brake checking people though, especially on motorways when you lift off to reset your foot. But it's so infrequent.

I can imagine some drivers might be on/off whilst getting used to a car with regen but if they are, I've yet to see one

theboss

7,536 posts

249 months

Sunday 13th November 2022
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It depends on the EV and the manufacturers implementation of regen braking.

Of the EVs I currently have:

Audi etron - regen can be automatic or manual including off. Regen still occurs under pedal braking.

Mini Se - regen can be set to one of two levels but not turned off. As far as I can tell the pedal always activates the friction brakes.

Of the two systems I much prefer Audi’s and tend to drive with regen manually controlled and disabled. Coasting is certainly better on a flowing road. I don’t personally like one pedal driving much, although it works in town.

Zero Fuchs

2,749 posts

48 months

Sunday 13th November 2022
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delta0 said:
They aren’t slowing down for no reason. Either keeping space with the car in front, change in speed limit or an obstacle.
Personally I see more flashing brake lights from idiots who tailgate. This is, and has been, a constant feature since I passed my test 30+ years ago.

I find regen promotes observation and a calmer driving style so see fewer, if any EV drivers tailgating. Although I'd expect this to change with greater numbers on the road. In the i3 I can slow down without the brake lights coming on but requires reading the road.


Pistonpants

277 posts

117 months

Sunday 13th November 2022
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Dashnine said:
Pistonpants said:
Best to turn regen off if you can. If you are a smooth driver coasting is more economical
Not convinced about that, certainly in my hybrid quite a bit of battery charge is regained by regen instead of braking, especially on a steeper hills.
When you are regenerating you are converting the cars stored kinetic energy to electrical energy in the battery, then back to kinetic energy again when you hit the gas. You get losses at each stage of conversion, so better to maintain the stored energy as kinetic if you can (ie coast). The case you mention going down a steep hill then obviously regen is better than braking where the energy is just lost as heat in the brakes, but usually if you hold the brakes lightly then that will regen rather than engage the mechanical brakes.

Dashnine

1,715 posts

80 months

Sunday 13th November 2022
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Pistonpants said:
Dashnine said:
Pistonpants said:
Best to turn regen off if you can. If you are a smooth driver coasting is more economical
Not convinced about that, certainly in my hybrid quite a bit of battery charge is regained by regen instead of braking, especially on a steeper hills.
When you are regenerating you are converting the cars stored kinetic energy to electrical energy in the battery, then back to kinetic energy again when you hit the gas. You get losses at each stage of conversion, so better to maintain the stored energy as kinetic if you can (ie coast). The case you mention going down a steep hill then obviously regen is better than braking where the energy is just lost as heat in the brakes, but usually if you hold the brakes lightly then that will regen rather than engage the mechanical brakes.
It depends what’s meant by ‘turn regen off’. Turning it off in the cars settings will allow more coasting without driver intervention but will prevent regen instead of braking downhill.

I temporally ‘turn regen off’ by using the accelerator to reduce the amount of regen if I wish to coast or keep the cars speed up down a less steep hill (as above).

If you believe the cars graphics (Cupra Formentor so the standard VW system?), the car will get to about 70% of available regen without using the brake pedal, and that increases to 100% with the brake pedal after which I assume that’s when the mechanical brakes come into effect.

raspy

2,714 posts

124 months

Sunday 13th November 2022
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F20CN16 said:
They don’t coast usually (unless there is an EV that allows you to select no regenerative braking). If you want to actually coast (at least in mine) you have to keep the accelerator depressed a little to cut out the regen.

It’s a new way of driving an EV vs ICE, where in an ICE you might lift completely off the pedal to coast, as above with an EV people are going to have to learn that they need to keep a little “throttle” on to coast. Though I suppose that’s like knocking an ICE into neutral. But then the brakes lights don’t illuminate when engine braking in an ICE.
Quite a few EVs coast and behave in a similar way to an ICE car when lifting off the accelerator.

The german ones are very good at having this option. So on motorways, with my iX, if you have adaptive regen on, and provided there a big enough gap to the car in front, the car will decide to coast for quite a long time.