1PD, regen, and brake lights

[Paul]

Do the brake lights come on during heavy regen? I've often wondered this even on my Maverick hybrid, You can push the regeneration pretty hard down selecting the low setting on the fly and I've never noticed that the brake lights come on but I can't see back there. If the regeneration is entirely the brake to stop, do the brake lights come on in other EVs with 1PD? Or at what point do they come on? Because you wouldn't want it to be coming on every time you had a mild regen. Seems like it could be a safety hazard if it didn't.

 

[AZFox]

Do the brake lights come on during heavy regen?

Yes.

 

[Ferrite]

Yup, a bit before I take my foot completely off the accelerator pedal, the brake lights come on. (EV6)

 

[EV Trek]

On both my previous Bolt and my Equinox EV they do, and they stay on with the hold function. It should be required, it seems like it would be a safety concern if it did not.

 

[usbritinusa]

Ummm, the one thing I hate when following other drivers is if they keep braking for no purpose. I have always assumed and observed that they are distracted while driving - like looking at their phone.

The fact that just taking your foot slightly off the gas will activate the brake light now puts me in that assumed distracted category which kinda sucks.

 

[clofan]

I hope so. Like you, my mav can slow down pretty quick on just regen but the brake lights DO NOT illuminate. Pretty dangerous when travelling on the highway, so I always push the brake a tiny bit to light the lamps.

 

[ClayJar]

This is a bit of a blast from the distant past of May, 2023. Back then, Alec of Technology Connections released an entire video about brake lights in electric cars, including specifically his 2022 Hyundai Ioniq 5 that did not activate the brake lights appropriately in heavy regen (see the Technology Connections video for reference or just delightful fun).

The video got a lot of traction. Consumer Reports did some testing and confirmed the problem, and a bit later Hyundai made a statement:

​

After further investigation, Hyundai and Genesis will be launching a field service campaign to update the EV brake light logic for the Hyundai IONIQ 5, Genesis Electrified G80, Genesis Electrified GV70 and Genesis GV60. There will also be a change made to new production of those models. Regardless of the accelerator pedal input, the brake lights will now turn on when the deceleration rate exceeds 1.3m/s2 (approx. 0.13 G). The service campaign will launch in July for approximately 56,000 vehicles and will be performed free of charge.​

​

So, it's apparently been an issue with some vehicles in the past, and it's also been something that's been solved after the fact before. Surely, nobody would be so out of touch as to have the same issue all over again, right? Right?

As for Slate, someone clip a camera (or just a mirror) to the back once we get test drives, and let's just verify that they handled it. (Surely, Slate people must watch Technology Connections, even if the Slate doesn't have a heat pump. 🤣)

 

[The Weatherman]

Ummm, the one thing I hate when following other drivers is if they keep braking for no purpose. I have always assumed and observed that they are distracted while driving - like looking at their phone.

The fact that just taking your foot slightly off the gas will activate the brake light now puts me in that assumed distracted category which kinda sucks.

I’m sure you meant to say Off the Accelerator. No Gas pedals here. 🤣

 

[2thlesswithta2s]

Ummm, the one thing I hate when following other drivers is if they keep braking for no purpose. I have always assumed and observed that they are distracted while driving - like looking at their phone.

The fact that just taking your foot slightly off the gas will activate the brake light now puts me in that assumed distracted category which kinda sucks.

I sometimes see cars with the brake lights on constantly while driving down the highway. I assume this means they're using the brake pedal as a foot-rest for their left foot. I also assume they have to frequently replace brake pads & rotors.

I grew up learning that the left foot was for the clutch & high-beam foot-switch. I also did my own brake pads, so had direct motivation to make them last & ability to directly see how much wear they experienced.

 

[EVfun]

I know the brake lights on my '04 Tacoma do NOT come on if I downshift from 5th to 3rd at speed. If there is anyone behind me I generally tap the brake pedal if I'm going to use aggressive engine braking. I hope the Slate is set up so the brake lights come on at a present g-force level of deceleration. I wonder, is it already a requirement for hybrids and EVs with regen?

 

[opensrc]

I sometimes see cars with the brake lights on constantly while driving down the highway. I assume this means they're using the brake pedal as a foot-rest for their left foot. I also assume they have to frequently replace brake pads & rotors.

Could be a bad brake switch too. The little stopper for mine disintegrated in my 2001 Civic and the brake lights just stayed on even with the car off

 

[bartflossom]

This is a bit of a blast from the distant past of May, 2023. Back then, Alec of Technology Connections released an entire video about brake lights in electric cars, including specifically his 2022 Hyundai Ioniq 5 that did not activate the brake lights appropriately in heavy regen

Alec caused me to overspend on the greatest toaster ever created by man.

 

[AZFox]

Alec caused me to overspend on the greatest toaster ever created by man.

There can only be one Greatest Toaster.

 

[kvermeer]

Ummm, the one thing I hate when following other drivers is if they keep braking for no purpose. I have always assumed and observed that they are distracted while driving - like looking at their phone.

The fact that just taking your foot slightly off the gas will activate the brake light now puts me in that assumed distracted category which kinda sucks.

Taking your foot slightly off the ~~gas~~ accelerator in an EV causes you to slow down much faster than just coasting, which should cause the brake lights to turn on whether you pressed the brake pedal/applied friction pads or whether you're just regenerating.

On that note, I'd argue that the lack of brake lights when you downshift for engine braking in an ICE vehicle is an antifeature, they ought to indicate strong deceleration by any means. And similarly, some people drive with their left foot hovering or gently resting on the brake pedal (a bad habit, I'd argue, but some people were taught that way and never corrected themselves), and cause the brake lights to flicker regardless of whether they apply it hard enough to actually close the gap from the pistons to the rotors. It should be measured by deceleration, not brake pedal travel.

See the Technology Connections video for reference or just delightful fun.

The video got a lot of traction. Consumer Reports did some testing and confirmed the problem, and a bit later Hyundai made a statement:

​

After further investigation, Hyundai and Genesis will be launching a field service campaign to update the EV brake light logic for the Hyundai IONIQ 5, ... the brake lights will now turn on when the deceleration rate exceeds 1.3m/s2...​

​

(Surely, Slate people must watch Technology Connections, even if the Slate doesn't have a heat pump. 🤣)

Love me some Technology Connections, and I've read enough posts from Slate engineers that I guarantee they either watch or would enjoy Alec too. If I were a wealthier man, I'd use the magic of buying two of them to have one Slate with which to do teardowns and one to drive, alas, there's not enough room in my garage or numerals in my bank account to make that happen.

 

[solartogo]

There can only be one Greatest Toaster.

That looks like a cute little truck... almost identical to my cute little truck!