EV regenerative breaking and no brake lights

[catfood12]

I've been using a relative's Corsa E for the last week. Very good car overall for tooling around town, and it has changed some of my prejudices about EVs.

I've been driving it in regenerative mode, and it does make a difference to the range. It slows down quickly when you take your foot off gas (power), and this seems to catch some drivers following unawares, that may be following too closely behind, or not paying attention, as the speed reduction I guess is similar to light breaking, but obvs no brake lights from the Corsa. This happens regularly.

I've had a couple of very close shaves, one this morning coming down a dual carriageway off slip and slowing from 70 to around 50 on regen, and cruising down the slip road before braking at the end.

I've never heard this mentioned or discussed anywhere else, and appears to me to be a significant aspect of driving an EV around, albeit in my limited experience. Have I missed something, am I doing it right ?!?

[sgtbash]

Are you sure it doesn't? In a Tesla it does - I assumed it was required by law.

[The test driver]

Yer, every EV I've driven when lifting off the accelerator to the point it starts regen activates the brake lights.

Might be worth a conversation with your dealer.

[aparna]

Maybe the corsa not have regen brake lights, similar to other EVs? Seems unlikely though.

[MOBB]

My Tesla certainly did, my current Mii electric, I'm going to check tonight now :-)

[JackJarvis]

Surely the brake lights still operate? It's still 'braking'. If not these are the ideal crash-for-cash vehicle

[catfood12]

Thanks for all of the speedy replies, double defo no brake lights on regen when you lift off the throttle. I've checked by looking at the car's reflection in a shop window at night, to check when the brake lights come on.

I didn't want to ask if other EVs did this, as I thought it was a stupid question. Although I was surprised that I didn't get brake lights under regen, then put it down to doubts as to how it would work, i.e. when does the ECU decide to put the brake lights on under regen, i.e. current level, speed etc.

My sister, who's car this is, doesn't use it in regen, as she doesn't know the option existed, so not had this issue! The car is two month old, It does sound like a trip to the dealers is required.

Thanks all.

[CraigyMc]

catfood12 said:

Thanks for all of the speedy replies, double defo no brake lights on regen when you lift off the throttle. I've checked by looking at the car's reflection in a shop window at night, to check when the brake lights come on.

I didn't want to ask if other EVs did this, as I thought it was a stupid question. Although I was surprised that I didn't get brake lights under regen, then put it down to doubts as to how it would work, i.e. when does the ECU decide to put the brake lights on under regen, i.e. current level, speed etc.

My sister, who's car this is, doesn't use it in regen, as she doesn't know the option existed, so not had this issue! The car is two month old, It does sound like a trip to the dealers is required.

Thanks all.

It may just be stellantis build quality steing through.

[Scrump]

catfood12 said:

I've never heard this mentioned or discussed anywhere else, and appears to me to be a significant aspect of driving an EV around, albeit in my limited experience. Have I missed something, am I doing it right ?!?

https://www.pistonheads.com/gassing/topic.asp?h=0&f=&t=1923948

https://www.pistonheads.com/gassing/topic.asp?h=0&...

[budgie smuggler]

I was curious and found someone else talking about this car on this forum:

https://www.speakev.com/threads/brake-lights-not-o...

Apparently it's only required over 0.17g, so maybe it just doesn't quite hit that.

Edited by budgie smuggler on Wednesday 13th October 14:25

[NS66]

Brake lights generally come on at a given speed - your test might show they dont come on under say 30 mph for example.
Best to get someone to check following you at speed using handsfree of course.

[TheDrownedApe]

stolen as i started to wonder about my ID.3. Although no idea what it feels like

[M1C]

budgie smuggler said:

I was curious and found someone else talking about this car on this forum:

https://www.speakev.com/threads/brake-lights-not-o...

Apparently it's only required over 0.17g, so maybe it just doesn't quite hit that.

Edited by budgie smuggler on Wednesday 13th October 14:25

Yes, i've been on that forum and topic too earlier, spooky coincidence?!

The mk1 Leaf didn't do it but i dont think it met the requirements, the regen wasn't/isn't as strong as some newer EVs. I think it has to meet a threshold of a particular deceleration before the law requires brake lights to be applied.

However, i do remember thinking that when i had my Leaf, i would have liked the brake lights to come on in B mode. The regen wasn't super strong...but even that was enough to catch people out behind who couldn't tell i was slowing down.

TLDR - yes. I think brakes should come on for decelerating regen, regardless.


EDIT - what the above says.

[carlove]

I’ve been behind a Corsa-e and got caught out by the brake lights no coming on, so gave an even bigger gap and worked off the car in front of the Corsa brake lights, Regen does slow quite sharply.

I have driven a leaf and the brake lights did come on with regen braking(I saw the reflection) it would put me off using the excellent (I really liked one pedal driving) feature if no brake lights came on.

[Bogga]

When using regen braking:

Outlander PHEV - Brake lights do NOT come on
Honde E - Brake lights DO come on

What is a bit annoying is following a EV driving in 'one pedal mode', brake lights on, lights off, on, off, on, off, etc etc...

[SWoll]

Bogga said:

When using regen braking:

Outlander PHEV - Brake lights do NOT come on
Honde E - Brake lights DO come on

What is a bit annoying is following a EV driving in 'one pedal mode', brake lights on, lights off, on, off, on, off, etc etc...

That's just bad driving as easing off the accelerator doesn't generate enough braking force to activate the brake lights IME, needs a considerable lift.

Outlander regen is obviously below the threshold required and more like the engine braking you would get with an ICE vehicle?

[RobDickinson]

Bogga said:

When using regen braking:

Outlander PHEV - Brake lights do NOT come on
Honde E - Brake lights DO come on

Strange my outlander PHEV certainly did put the brake lights on, are you on max regen?


Afik brake lights on deceleration for evs is a UN vehicles mandate at x m/s rate , probably whats from the VW manual above looks about right (0.7ms)

[so called]

Brake lights came on with my i3 but it depended on how much I feathered the power.
I compared it to engine breaking so was quite relaxed about the performance.
My Ioniq 5 is the same.

[Russ T Bolt]

RobDickinson said:

Bogga said:

When using regen braking:

Outlander PHEV - Brake lights do NOT come on
Honde E - Brake lights DO come on

Strange my outlander PHEV certainly did put the brake lights on, are you on max regen?

I was about to say the same, From memory only level 4 and 5 lit up the brake lights.

[Lancelot]

Russ T Bolt said:

RobDickinson said:

Bogga said:

When using regen braking:

Outlander PHEV - Brake lights do NOT come on
Honde E - Brake lights DO come on

Strange my outlander PHEV certainly did put the brake lights on, are you on max regen?

I was about to say the same, From memory only level 4 and 5 lit up the brake lights.

Level 5 on the Outlander certainly does