Max Regen "Braking " Status Light

sentience

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Maybe I'm just an idiot and missing something here:

Are there any dash lights or other status lights / bars that turn on when max regen is in the "braking" mode?
I've had a few moments where I couldn't tell if I was braking or coasting - specifically, it would be nice to know if my rear brake lights were on.

I'm looking for something that has a very clear braking (e.g. red), coasting (e.g. yellow), and power (e.g. green) indicator.





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michail

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I figured this out with the help of another member.

Basically, the battery regen gauge is your best indicator. You can even feather the braking with light throttle input so the stopping isn't as abrupt. Lower throttle than what your current speed calls for with brake regen. It's almost like negative braking.

I'm still not sure if the brake lights trigger while your foot is still applying some pressure.
 
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sentience

sentience

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I'm still not sure if the brake lights trigger while your foot is still applying some pressure.
And that's why it's a safety issue.

I'm specifically looking for some kind of indicator when the brake light is on during max regen driving. So far, none of the gauges appear to have that.
 

michail

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I very have the same concern. I'm a very defensive driver have a good 360 awareness. I may do a test with my son watching to see what it does.
 

SnB4xe

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I believe there are standards to regulate when the brake light comes on with 1 pedal driving. I know it's true for Europe but not sure if NA has adopted those yet. The brake light is triggered by measured deceleration in negative g force. Not sure what that figure it exactly....

At any rate, doesn't apply to us since the 4xe doesn't have 1PD. When using Max Regen it is no different than a regular ICE vehicle with manual transmission and lifting off the throttle. The engine braking effect is about the same (depending on what gear you are in of course). So, it's not really a safety issue per se......the driver behind still needs to pay attention and not collide with the vehicle in front when they are slowing down without touching the brake pedal.
 

Jocko

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I believe there are standards to regulate when the brake light comes on with 1 pedal driving. I know it's true for Europe but not sure if NA has adopted those yet. The brake light is triggered by measured deceleration in negative g force. Not sure what that figure it exactly....

At any rate, doesn't apply to us since the 4xe doesn't have 1PD. When using Max Regen it is no different than a regular ICE vehicle with manual transmission and lifting off the throttle. The engine braking effect is about the same (depending on what gear you are in of course). So, it's not really a safety issue per se......the driver behind still needs to pay attention and not collide with the vehicle in front when they are slowing down without touching the brake pedal.
Are you saying that the negative g’s that result from the motor/generators switching into generator mode during max regen wouldn’t be enough to cross that European threshold?
 

Rubicon 4xe

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Maybe I'm just an idiot and missing something here:

Are there any dash lights or other status lights / bars that turn on when max regen is in the "braking" mode?
I've had a few moments where I couldn't tell if I was braking or coasting - specifically, it would be nice to know if my rear brake lights were on.

I'm looking for something that has a very clear braking (e.g. red), coasting (e.g. yellow), and power (e.g. green) indicator.
Chris Hall (member of this forum) created a channel on YouTube that has a lot great videos in regards to the Wrangler 4xe that you may want to subscribe to. The attached link to Chris Hall’s video answers your question regarding the brake light during max regen.

 

SnB4xe

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Are you saying that the negative g’s that result from the motor/generators switching into generator mode during max regen wouldn’t be enough to cross that European threshold?
It can easily cross that threshold. So cars that have 1PD systems are required to activate the brake lights at that point. The way I read the regulations......an EV without 1PD isn't required to comply with the regulation.

In my Mach-E, in 1PD mode the brake lights come on when the accelerator pedal is fully released. In normal mode, the brakes lights only come on when I touch the brake pedal irregardless of the regen setting I am in at the time. Not sure why Ford did it that way but appears to be somewhat consistent with other electrified vehicles that I have studied.
 

Jocko

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It can easily cross that threshold. So cars that have 1PD systems are required to activate the brake lights at that point. The way I read the regulations......an EV without 1PD isn't required to comply with the regulation.

In my Mach-E, in 1PD mode the brake lights come on when the accelerator pedal is fully released. In normal mode, the brakes lights only come on when I touch the brake pedal irregardless of the regen setting I am in at the time. Not sure why Ford did it that way but appears to be somewhat consistent with other electrified vehicles that I have studied.
Oh sorry in my previous post I was referring to the 2 motor/generators in the 4xe. Trying to understand why brake lights wouldn’t be needed for max regen. Unless I misunderstood your post that I replied to. I’ve been know to do that from time to time. 🤪
 
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sentience

sentience

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Chris Hall (member of this forum) created a channel on YouTube that has a lot great videos in regards to the Wrangler 4xe that you may want to subscribe to. The attached link to Chris Hall’s video answers your question regarding the brake light during max regen.

That video didn’t answer my question. Are there any dash lights that indicate if the brake lights are on during regenerative braking?

if not, this should be added. It’s ridiculous a driver isn’t told for certain if their brake lights are on. With normal braking it’s a non-issue, since you are the one activating the brakes.
 

SnB4xe

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Oh sorry in my previous post I was referring to the 2 motor/generators in the 4xe. Trying to understand why brake lights wouldn’t be needed for max regen. Unless I misunderstood your post that I replied to. I’ve been know to do that from time to time. 🤪
No worries......I am not sure why either. It's a topic on several EV forums I believe. "Why do brake lights work in 1 pedal mode and not when using a max regen setting?" As near as we can tell, there appears to be regulations/standards for 1 pedal driving modes that specify when the brake lights need to be activated and those usually correspond to some level of negative g force reading. However, if the driver isn't using a 1 pedal system (or the vehicle doesn't have a 1 PD mode), then the standards don't apply provided the max regen setting is selected by the driver. Either by pressing a button or pulling a lever for example.

The conclusion drawn is that when the driver selects a max regen setting (that defaults back to normal during the next key cycle), then the brake lights aren't required to activate because that would be a similar situation as releasing the accelerator on a manual transmission ICE vehicle or selecting a low range in an automatic transmission ICE vehicle. In both those situations, the brake lights don't apply either so it's treated the same.

My personal opinion is if a vehicle has a 1 pedal driving mode anyway.....then it must have the software calibrated to measure negative g force so why not allow the brake lights to come on even when the driver isn't using 1 PD but selected a max regen mode? A little extra safety is always a good thing IMO.

Since the 4xe doesn't have a 1 PD feature then the software isn't there so they can get away with not activating the brake lights because the regulation may not apply.
 

SnB4xe

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That video didn’t answer my question. Are there any dash lights that indicate if the brake lights are on during regenerative braking?

if not, this should be added. It’s ridiculous a driver isn’t told for certain if their brake lights are on. With normal braking it’s a non-issue, since you are the one activating the brakes.
There might be some fiber optic solution we can purchase (or build ourselves).
If we drill a pair of tiny holes in the 3rd brake light housing and install some fiber optic cables with a lens on one end then we can see in our rear view mirror when those brake lights come on.

Could also add in another led and fasten it to the back side of that housing so you can see it in the rear view mirror.

Or, add a brake light that plugs into the trailer connector and mount the lamps in the back somewhere visible by the mirror.

Seems like a fun weekend project....
 

Rubicon 4xe

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That video didn’t answer my question. Are there any dash lights that indicate if the brake lights are on during regenerative braking?

if not, this should be added. It’s ridiculous a driver isn’t told for certain if their brake lights are on. With normal braking it’s a non-issue, since you are the one activating the brakes.
True there are no dash lights that tell you your brake light is on or off. I have faith in my Jeep that when I put my foot on the brake the brake lights come on. After watching Chris’s video, I have faith that when I take my foot off of the accelerator the max regen brake light system is working. For me, neither system requires a dash light.
 

SnB4xe

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That video didn’t answer my question. Are there any dash lights that indicate if the brake lights are on during regenerative braking?

if not, this should be added. It’s ridiculous a driver isn’t told for certain if their brake lights are on. With normal braking it’s a non-issue, since you are the one activating the brakes.
That is a good video. Thanks for posting.
It demonstrates that Jeep has programmed the brake lights to illuminate while slowing down even though it isn't a regulated requirement. Very nice to know that Jeep has decided to include that safety feature.
 

michail

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I'm going to test this some way. For one, I can come to a near stop with max regen on and still have the pedal depressed. There isn't much play but it's there. It's fairly abrupt if you just lift off. Harder than I normally would like to brake.

Also, feels like the primary brake is still the regen even with the brake pedal.

Usually I'll only hard brake if I'm trying to give those behind me access to a turning lane with a green light.

Also, I always check my back to see if the driver behind me notices. IMO, it's courteous but some just find it irritating and want to get to the traffic like in a hurry.
 

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