Does high regen turn the brake light on?

[Simon853]

High re-gen slows the car quite dramatically, more so that I'm used to with ICE cars and therefore more than drivers behind me might expect. So, I wonder, does it apply the brake light to warn the driver behind it's dropped the anchor?

Si

 

[Goldwing]

High re-gen slows the car quite dramatically, more so that I'm used to with ICE cars and therefore more than drivers behind me might expect. So, I wonder, does it apply the brake light to warn the driver behind it's dropped the anchor?

Si

Yes

 

[Simon853]

That's a relief, thanks! ?

 

[AndyL61]

Is there a level on our cars at which the brake lights operate. I've seen figures banded about of -6% to -8% but no actual proof of what the number actually is ?

 

[Bam Bam]

Yeah - I've wondered this. You can't see it happen if you are in the driver's seat. Was thinking I'd need to get a friend to drive behind to confirm (if I was that bothered)!

 

[Simon853]

I'd taken to dabbing the brake when slowing to a roundabout, but good to know I don't need to.

 

[KenD]

I followed my car a few times when my wife was driving. I noticed that the car was slowing down but the brake lights weren't on. It was in day time. I might try in the evening.

 

[PaulD]

EU regs require the brake lights to come on above a certain deceleration rate. I can’t remember what the number is, but obviously in the MG4 whether it comes on will depend on regen level and battery level.

 

[Simon853]

And software bug level probably! ?

 

[KenD]

The regen level is set to 3

 

[MrPeaski]

if you look on the drivers display at the bottom where its shows the power level.
Normally it is in white so the figures are 1 to 100% so power output, when in regen the figure goes green and - (minus) figures from -1 to -25% (I think)
The brake lights come on at around -6 or -7%

 

[Rolfe]

One winter evening when I was following a Leaf along a rather windy road I wondered why on earth he kept braking. Then I realised he wasn't, it was just his regen coming on.

I've seen my own brake lights come on, reflected in something behind me, when I've taken my foot off the accelerator.

 

[AndyL61]

if you look on the drivers display at the bottom where its shows the power level.
Normally it is in white so the figures are 1 to 100% so power output, when in regen the figure goes green and - (minus) figures from -1 to -25% (I think)
The brake lights come on at around -6 or -7%

How do you know the brake lights come on at -6 or -7% . That's the point of my question.

 

[Ian Key]

How do you know the brake lights come on at -6 or -7% . That's the point of my question.

At night you can see the reflection of your brake lights in your rear view mirrors especially if there is a refelective road sign behind you.

 

[Jonknee]

At regen level 1, the car shows -4% when lifting off the accelerator. As this is the closest to engine braking in an ICE, I assume no brake lights illuminated.Doesn’t answer your question as to what level the lights come on though. Sorry

 

[AndyL61]

At night you can see the reflection of your brake lights in your rear view mirrors especially if there is a refelective road sign behind you.

So far I've never managed to see my brake lights reflected, only when I am on the brakes at very low speed reflected in the vehicle behind.

 

[Anon70]

Not sure if cars made for the UK market have to follow these regs but this might be the tech spec for when a brake light signal must be generated

Sourced from here

https://unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/R13hr2e.pdf

 

[siteguru]

Agreed. And 1.3 m/s² equates to roughly -7% regen in the MG4.

Therefore regen level 1 probably won't cause the brake lights to activate, but levels 2, 3 and Adaptive will.

 

[TerryN]

I'm usually on level 3 regen and mine definitely activates the brake lights. Around -7% sounds about right.

 

[r1chardbwrn]

On a dark wet night I have definitely seen the brake lights come on in rear view mirror. I think the regen was on level 3 but this was our FL MG5.