Regenerative braking and range

[borski]

It seems you are misunderstanding what I'm trying to convey.
After 5 or so miles of driving with many larger decreases in speed (45 mph to 15 mph ) combined with a fairly steady decent 5% to 10% with a peak 24% (according the a popular bicycling web site) negative grade, I've noticed a decrease in regen. This will occur at one of the less steep curves near the bottom where I will get significantly less braking effect.
This has never happened more than once on a trip down the hill, but it has happened on three separate trips down the hill.
The first two times I thought I was misjudging how the car was reacting. But after the third time I am sure there is less braking action. This never happened during winter ski season. It did happen during spring skiing when temperatures were in the 60s.
I will likely not be making this trip with the Lucid again until December (ski season). Most trips in the summer I need to transport equipment (cement mixer, scaffolding, etc) that require the pickup truck.
I drive this hill 12 to 20 times a year (and have for the last 25 years). So I'm very familiar with the curves and pitches and do not believe I am misreading the situation.

Huh! Well, to be clear, I wasn't arguing - just trying to understand. Sorry if it came off as anything else.

Anyway, here's hoping they add an indicator when regen is limited. One can hope!

 

[hmp10]

I have had a loss of regen at much less than 80%. Parking near the top of a hill plugged into a 120v outlet for two days and charged to close to 80%.
Leaving the Lodge I drive down a hill that varies between 5% and 14% grade down. It is a winding road where I accelerate to 40 (pressing accelerator but using little power) and slow quite quickly to 15 (using mostly regen). This is a steady down hill for approximately 10 miles with a total elevation loss of 1500 feet.
Not an alot of total elevation but fairly steep, steady and alot of drastic slowing events. Usually just before town I'll slow for the last switchback and have no regen.

This may be a software issue. We were on a visit to Charleston, SC with our first DE during the UX 1.0 nightmare. One afternoon while driving around town with about 60% charge, regen came and went randomly. I'd approach one stop light, coming to a full stop with one-pedal driving. Approaching the next light, I got absolutely no regen and had to go full on the brake pedal. The problem disappeared for the rest of the day once the car reset during a meal break, but it returned the next day, again disappearing after a reset. For some reason it happened only in Charleston on that trip and nowhere else before or since.

 

[Jester1868]

For what it’s worth, coasting in neutral on a downgrade is illegal in many states.

“The driver of a motor vehicle when traveling on down grade upon any highway shall not coast with the gears of such vehicle in neutral.”

So is speeding but... lol

 

[Jester1868]

I would not shift the Air while in motion. Neutral is sort of difficult to engage in the first place; you could easily accidentally throw it into reverse. And I don’t think there would be any benefit mechanically, anyway.

You can shift into N halfway in either direction so just go down instead of up.

 

[Steveinarizona]

Didn't like that what about Porsche's take

https://cars.usnews.com/cars-trucks/features/porsche-says-no-to-one-pedal-driving

Here is another:

Is Coasting Better Than One-Pedal Driving? | GreenCars

Is it better for you to coast or go the one-pedal driving route? Learn more from GreenCars here.

www.greencars.com

This has been an open argument. It also may depend upon whether the car uses a blended braking system (e.g., Porsche, Genesis, etc.) or a friction only braking system (Tesla/Lucid). In a blended braking system, the initial depression of the brake pedal initiates regen; further or sudden depression initiates friction braking. Different cars, even different models, offer different levels of regen driving.

Just for kicks and giggles I have tried different levels of regen and have not seen a big difference in efficiency on my GV60P. What does make a big difference, for me, is fast acceleration, high speed driving, extreme temperatures, always on HVAC, etc. Good thing I don't care about efficiency.

So my suggestion is to settle on what feels best and most natural to the driver. Put differently, the Lucid is a driver's car so DRIVE IT.

 

[fisheral]

Here is another:

Is Coasting Better Than One-Pedal Driving? | GreenCars

Is it better for you to coast or go the one-pedal driving route? Learn more from GreenCars here.

www.greencars.com

This has been an open argument. It also may depend upon whether the car uses a blended braking system (e.g., Porsche, Genesis, etc.) or a friction only braking system (Tesla/Lucid). In a blended braking system, the initial depression of the brake pedal initiates regen; further or sudden depression initiates friction braking. Different cars, even different models, offer different levels of regen driving.

Just for kicks and giggles I have tried different levels of regen and have not seen a big difference in efficiency on my GV60P. What does make a big difference, for me, is fast acceleration, high speed driving, extreme temperatures, always on HVAC, etc. Good thing I don't care about efficiency.

So my suggestion is to settle on what feels best and most natural to the driver. Put differently, the Lucid is a driver's car so DRIVE IT.

Agreed, Swift-Standard is essentially perfect for me.

 

[terrycs]

I found that the best way to hyper mile is in max regen and do the best I can to minimize the amount the charge/discharge indicator goes into the discharge range (on the right) and maximize the amount the amount the charge/discharge indicator goes into the charge range (on the left).

 

[Amster]

I found that the best way to hyper mile is in max regen and do the best I can to minimize the amount the charge/discharge indicator goes into the discharge range (on the right) and maximize the amount the amount the charge/discharge indicator goes into the charge range (on the left).

I used to do that a lot when I had my last car, a PHEV with a 35 mile battery range. I'd try to make it last as long as it could. This one, I don't worry about too much.

 

[kort6776]

I found that the best way to hyper mile is in max regen and do the best I can to minimize the amount the charge/discharge indicator goes into the discharge range (on the right) and maximize the amount the amount the charge/discharge indicator goes into the charge range (on the left).

hypermile? are the nerds still doing that? the purpose of a car is to transport me from place to place at optimal speed. The Air currently has EVs that offer the highest ranges despite the reality that the "bogus" claims of range can never be met. my rule thumb is to knock 20% off of whatever the guess o meter is reporting, more range needs to deducted if there are climatic issues or large upgrades that need to be driven.

 

[terrycs]

hypermile? are the nerds still doing that? the purpose of a car is to transport me from place to place at optimal speed. The Air currently has EVs that offer the highest ranges despite the reality that the "bogus" claims of range can never be met. my rule thumb is to knock 20% off of whatever the guess o meter is reporting, more range needs to deducted if there are climatic issues or large upgrades that need to be driven.

You can rest assured … I didn’t buy one of these to hypermile.

 

[HariK]

I don’t know the physics, so I’m not going to pretend to be an expert. All I know is when I drive downhill from Nederland (8200 ft) to Boulder (5600 ft) on high regen, I end up with a few kWh MORE in my battery pack than when I started. That would not happen with coasting. I might end up using almost no energy that whole way down, but I wouldn’t be gaining energy.

I had the same exact experience driving from Mt rose to south lake Tahoe with max regen and 1 pedal driving

 

[Daniel2022AT]

Weak regen makes no sense logically if the goal is max efficiency. Either coasting plus friction braking is better than regen or regen is better. So a combination will not maximize efficiency. Simple logic.

The laws of physics tell us regen is actually significantly better than coasting. I have found regen to significantly boost efficiency in urban driving.

Of course, driving technique matters. If you goose it right after regen slows it down, you can easily throw the efficiency gains out the window. It does take certain skill.

I’ve been driving a Kia EV6 as a loaner while my Lucid is in the body shop. I like the real time efficiency gauge at the bottom of the dash displays. It is very instructive to get immediate real-time feedback.

Old mindsets and old driving behaviors are hard to break. Most younger drivers take to regen instinctively.

Regarding hypermiling, anyone can do whatever the flip they want. If a driver wants to achieve 5 mi/kWh in a Lucid Air, God bless you and go set a new world’s record for efficiency if that’s what you want to do.

 

[hmp10]

I’ve been driving a Kia EV6 as a loaner while my Lucid is in the body shop. I like the real time efficiency gauge at the bottom of the dash displays. It is very instructive to get immediate real-time feedback.

Lucids used to display this information on the Glass Cockpit, and I, too, found it very useful. The information can still be had, but it's deeper down in the menus now and, I think, only available when the navigation system is engaged. I would love to have the old display back on the default screen. It was one of the updates that went backwards in my view.

Old mindsets and old driving behaviors are hard to break. Most younger drivers take to regen instinctively.

I was 63 years old when we got our first EV -- a 2015 Tesla Model S P90D. It took me all of 20 minutes to fall in love with regenerative braking, and I keep it set to maximum in the two EVs we've bought since. One of the most annoying things about driving our last remaining ICE vehicle is having to get on and off the brake pedal in traffic.

 

[BillHartman67]

Weak regen makes no sense logically if the goal is max efficiency. Either coasting plus friction braking is better than regen or regen is better. So a combination will not maximize efficiency. Simple logic.

The laws of physics tell us regen is actually significantly better than coasting. I have found regen to significantly boost efficiency in urban driving.

Of course, driving technique matters. If you goose it right after regen slows it down, you can easily throw the efficiency gains out the window. It does take certain skill.

I’ve been driving a Kia EV6 as a loaner while my Lucid is in the body shop. I like the real time efficiency gauge at the bottom of the dash displays. It is very instructive to get immediate real-time feedback.

Old mindsets and old driving behaviors are hard to break. Most younger drivers take to regen instinctively.

Regarding hypermiling, anyone can do whatever the flip they want. If a driver wants to achieve 5 mi/kWh in a Lucid Air, God bless you and go set a new world’s record for efficiency if that’s what you want to do.

Agree with Daniel...

I don't think this is a very difficult concept??

• Coasting wastes 100% of the kinetic energy in a deceleration. No energy is recovered. (I don't think anyone disagrees?)
• Regen captures some % of the kinetic energy in a deceleration. Some energy is recovered. (I don't think anyone disagrees?)

With Regen you can drive further on the captured energy.

Whether you prefer Coasting or Regen is a "Personal Preference". I like to accelerate Hard (Personal preference). I know it isn't efficient, but I don't care.

 

[hmp10]

Agree with Daniel...

I don't think this is a very difficult concept??

• Coasting wastes 100% of the kinetic energy in a deceleration. No energy is recovered. (I don't think anyone disagrees?)
• Regen captures some % of the kinetic energy in a deceleration. Some energy is recovered. (I don't think anyone disagrees?)

With Regen you can drive further on the captured energy.

Whether you prefer Coasting or Regen is a "Personal Preference". I like to accelerate Hard (Personal preference). I know it isn't efficient, but I don't care.

Yep. There is a reason that every EV maker -- including even the Germans who want to fool their drivers into thinking they're using friction brakes -- makes use of regenerative braking as part of their range-enhancing strategy.

 

[terrycs]

Interesting video clip I saw demonstrating tow charging an EV. Since the Air has better mi/kWh, can it recover more during regen braking?

 

[amulet]

Agree with Daniel...

I don't think this is a very difficult concept??

• Coasting wastes 100% of the kinetic energy in a deceleration. No energy is recovered. (I don't think anyone disagrees?)
• Regen captures some % of the kinetic energy in a deceleration. Some energy is recovered. (I don't think anyone disagrees?)

With Regen you can drive further on the captured energy.

Whether you prefer Coasting or Regen is a "Personal Preference". I like to accelerate Hard (Personal preference). I know it isn't efficient, but I don't care.

I would disagree with the above statement.

The energy stored in battery is (mostly) used to accelerate the car (converted to kinetic energy). No matter how you look at it, this energy is eventually lost to friction (air, tires, etc.), but also to other inefficiencies (battery, inverter, motor, etc.).

Regeneration braking captures <100% of the kinetic energy (probably less than 70%) due to friction and various other losses (motor, inverter, battery, etc.). The captured energy will be inevitably lower than the kinetic energy of the moving car. Whatever is recovered will still be "wasted" eventually.

On the other hand, during coasting the kinetic energy would mostly be lost to friction only.

Therefore, the main advantage of the regeneration braking over coasting is that you can use the captured energy at some later time [but it comes at a price - less than 100% of the energy is recovered] as opposed to coasting where you "waste" 100% the energy right away. There is obviously a clear advantage in using regenerative braking over the regular (friction based) braking.

Imagine that you alternate rapid acceleration and (regenerative) braking every second (let's pretend friction losses do not exist). Obviously due to energy conversion losses you will end up losing more energy compared to just driving at more or less constant speed.

 

[segbrk]

Coasting doesn't waste energy... braking wastes energy. And you can coast with high regen on, you just don't take your foot off the accelerator. Keep the Charge/Power meter in the middle. That's coasting.

 

[borski]

Coasting doesn't waste energy... braking wastes energy. And you can coast with high regen on, you just don't take your foot off the accelerator. Keep the Charge/Power meter in the middle. That's coasting.

Yes. People here are referring to “coasting” in the classic sense, which means you are losing power over time, just without friction braking.

Actual coasting is simply riding at the same speed with no additional power, simply due to inertia. If you can keep moving forward without using power, then coasting is better, but regen should be used when you NEED to brake. This combination will give you the best efficiency per mile.

Alternatively, just drive with a single pedal and get the best of both worlds, because the losses are minimal.

If you truly want to hypermile, turn on ACC and make sure nobody is ahead of you. That will coast for you, and will only use regen when it needs to break.

 

[segbrk]

Yes. People here are referring to “coasting” in the classic sense, which means you are losing power over time, just without friction braking.

Yeah, if you keep that meter in the middle, road friction and air resistance are going to slow you down, because you're not applying any more power. It's the same thing. Obviously we're not perfect at balancing that, but it's easy to be Close Enough.