Regen Braking and Brake Lights

[hydbob]

Watched a YT video on this matter and came to the forum in a panic wondering if my beloved Lucid is failing this key functionality - properly illuminating the brake light when decelerating by regen. Wish Lucid would publish spec on what triggers it.

This YT video by Technology Connections mentions that the EU recently patched up their regs on when brake lights come one, setting it at min (or max?) of 1.3m/s^2 deceleration, but looks like NHTSA has not done so yet. It's a long video, but very interesting and well-researched.

Anyone have an accelerometer to add some further data to @CrewChief 's experiment? Can't our phones do that? Is there an app for that?

Have you had someone follow you while on the phone to just see for yourself?

 

[AnthonyInCO]

Well no, but for the next level of accuracy I had in mind, I don't think a person following and reporting via phone would cut it due to cell phone latency and human reaction time.

What I'm thinking is dual GoPros with time stamps synchronized, and an accelerometer or accelerometer phone app (If phone accelerometers can accurately measure deceleration), with one GoPro pointed at the accelerometer and the other GoPro mounted to the car's trunk or inside rear window to capture brake light glare. Unfortunately, I have neither GoPro cameras nor an accelerometer

Or, a Lucid technician or insider just telling us! Surely, the brake light trigger by regen is in a technical manual or spec sheet somewhere.

 

[hydbob]

Well no, but for the next level of accuracy I had in mind, I don't think a person following and reporting via phone would cut it due to cell phone latency and human reaction time.

What I'm thinking is dual GoPros with time stamps synchronized, and an accelerometer or accelerometer phone app (If phone accelerometers can accurately measure g-force), with one GoPro pointed at the accelerometer and the other GoPro mounted to the car's trunk or inside rear window to capture brake light glare. Unfortunately, I have neither GoPro cameras nor an accelerometer

Or, a Lucid technician or insider just telling us! Surely, the brake light trigger by regen is any technical manual or spec sheet somewhere.

Sure but if they told you it's 1.3m/s^2 would you know where that is on the energy meter?

 

[AnthonyInCO]

Sure but if they told you it's 1.3m/s^2 would you know where that is on the energy meter?

Isn't that what acceleration is measured in? I had said g-force, but that's just another derived unit of acceleration. Don't accelerometers give measurements in m/s^2?

And while the EU mandates that now, doesn't mean Lucids here in the US abide by that, and also the EU reg states the lights must come on at that point - they could come on earlier.

 

[hydbob]

Isn't that what acceleration is measured in? I had said g-force, but that's just another derived unit of acceleration. Don't accelerometers give measurements in m/s^2?

And while the EU mandates that now, doesn't mean Lucids here in the US abide by that, and also the EU reg states the lights must come on at that point - they could come on earlier.

You can modulate regen yourself and record an accelerometer with 1 GoPro and just have someone follow with the phone and indicate when the brake lights turn on and sync that together with your video. Not sure how accurate the phone accelerometer is though, that would be the biggest variable imo.

 

[pjdcorp]

That’s a really good question and the answer is yes. I do wish I knew WHEN it was activating the brake lights. How strong of a regen? What if I just let off a little on the freeway? I wish the little icon on the dash would have brake lights that light up to indicate.

Agreed.

 

[suchluke]

Did anyone else notice this? When using regen to come to complete stop the brake lights come on as expected. When the car is close to complete stop the regen/breaking is reduced causing brake lights to turn off until the hold function activates then brake lights come on. I rarely use the brake pedal and I find is as potential issue. I noticed that drivers behind me tend to accelerate thinking I about to start moving again then braking suddenly very close to my rear end. It happened numerous times. I know if they would keep more distance it wouldn't be a problem. I wish that Lucid will adjust the functionality/sensitivity, so the brake lights stay on until complete stop.

 

[bill1745]

Curious, how did you track it? Put a mirror on the back? Drive at night to see? Have a follow car?

The post says he had a follow car.