Regenerative braking and range

[Pittsburgher]

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.”

the range gained by trying such tricks is minimal at best and not worth the bother.

Not unlike BMW making complex alternators and "smart" battery charging electronics that result in the aforementioned $700 battery replacement. Assuming a car battery last 7 years, what are the MPG gas savings and extended fuel savings for that 7 year period ? If I had to guess, probably "minimal at best, and not worth the bother" (unless you consider the $ made by BMW and their dealerships vs. a normal $150 battery replacement requiring 15 minutes labor). Obviously a pet peeve of mine ! !

That said, still curious if anyone knows the mechanics and/or electronics behind our Lucids "neutral" ? Is there a clutch that disengages motor(s) from drivelines/axles ? For dual motor cars (all but Pure) are there 2 clutches ? Maybe some means other than a clutch - like applying just enough energy into the motors to make them feel like they are in neutral (like an electronic version of feathering the accelerator to be in between accelerating and regen ?

IIRC, electric motors have a decent amount of internal resistance when not being driven (because of the magnets) . . . ie if one goes to manually turn an "unplugged" electric motor it takes significant effort to overcome the force of the magnets. . . no ?

 

[hmp10]

IIRC, electric motors have a decent amount of internal resistance when not being driven (because of the magnets) . . . ie if one goes to manually turn an "unplugged" electric motor it takes significant effort to overcome the force of the magnets. . . no ?

I don't know anything about your other questions, but motor "drag" from magnets is a characteristic of permanent magnet motors (which Lucid uses) but not of induction motors (which Tesla used to use but are now either replaced by permanent magnet motors or used on one axle with a permanent magnet motor on the other).

Each technology has its advantages and disadvantages, but permanent magnet motors are more efficient in most use cases for EV propulsion. However, they experience an effect called "cogging" which can make the car feel as if it's cycling through surges at low speeds. One of the reasons Tesla used a permanent magnet motor on one axle and an induction motor on the other was to gain some of the efficiencies of the permanent magnet motor but to enable low-speed propulsion of the car without cogging effects by disengaging the permanent magnet motor and using only the induction motor.

One of the motor breakthroughs Lucid made with the Air was to reduce significantly the cogging effect in permanent magnet motors, thus allowing them to be used on both axles for their greater efficiency.

 

[Buffalo Bob]

I don't know anything about your other questions, but motor "drag" from magnets is a characteristic of permanent magnet motors (which Lucid uses) but not of induction motors (which Tesla used to use but are now either replaced by permanent magnet motors or used on one axle with a permanent magnet motor on the other).

Each technology has its advantages and disadvantages, but permanent magnet motors are more efficient in most use cases for EV propulsion. However, they experience an effect called "cogging" which can make the car feel as if it's cycling through surges at low speeds. One of the reasons Tesla used a permanent magnet motor on one axle and an induction motor on the other was to gain some of the efficiencies of the permanent magnet motor but to enable low-speed propulsion of the car without cogging effects by disengaging the permanent magnet motor and using only the induction motor.

One of the motor breakthroughs Lucid made with the Air was to reduce significantly the cogging effect in permanent magnet motors, thus allowing them to be used on both axles for their greater efficiency.

Interesting! I do a lot of low speed slogging through my building's parking garage, and have never noticed the slightest bit of 'cogging'... while I'm 'slogging'.

 

[AlignTrex]

I like regen braking, but it is making my leg weak!

When I owned a manual BMW both of my legs were strong. Then when I went to automatic only my right leg was getting a workout shifting between accelerator and braking pedal.

Now, I barely have to move any of my legs! Soon, I won’t even have to move my arms. Eventually I’ll have chicken legs with Trex arms!