Variable Regen

[kerbe2705]

My understanding is that there are those who prefer to NOT use Adaptive Cruise Control when driving longer distances on highways and want to be able to “coast” at will.

My personal choice is to allow the vehicle to decide when it wants to coast and when it wants to regen to maintain a constant speed.

There may also be some Luddites in the EV community who either distrust or dislike the “feel” of regenerative braking and choose to rely solely on friction braking…

[RajGiandeep]

My EV experience with regen is a ’13 Leaf. Which doesn’t have very strong regen. Depending on the road. Sometimes I do put it in neutral to coast to extend my range instead of having to float the pedal just right.

I mentioned this on the previous forum. But would be nice to be able to switch to neutral or switch between regen (light, medium, heavy) easily while driving.

[llewellyn-evans]

Turning off regen in an Aptera will be a totally different experience to any other EV because the drag coefficient is so low. She is going to keep going much faster than any PA (Pre-Aptera) EV. Down hill with no regen will be like being on a street luge.

[jaron-harding]

neat idea, see who can set the longest coasting record 🙂

[Biker]

For now, it seems Lightyear has it:

Lightyear 0 Proves Another Advantage of Sharp Aerodynamics: Coasting Gets You Further (autoevolution.com)

[hans-roes]

I’ve been driving an Ioniq now for a little over 2 years and I play with my regen settings on every drive.

Contrary to popular believe, full regen is not the most economical way to drive. When regenerating power, you lose a lot of it with all the conversions that you have to make. Ultimately, you will only be able to put about a third of the power back to work for you, losing about two thirds in the regeneration. So, when driving on a highway or in free flowing traffic, I turn off regeneration, that way if I need to cruise a little, or just lose a little bit of my speed (e.g. approaching a lower speed limit with no traffic behind me), I can just let friction take the speed away and that is more efficient than actually slowing down faster with regen and putting some energy back in the battery,

When in heavy traffic, I want heavy regen. I’ll be accelerating and decelerating a lot and having lots of regen means I have to use the brake pedal a lot less. And when in normal traffic, I’ll take light regen, that way, when I lift off from the accelerator, I get some engine braking and the behavior is similar to ICE cars which is also more comfortable for the cars behind me.

I do know not every EV driver likes to play around with those settings and plenty of drivers leave them at the default of light regen because that’s what they are used to. But selecting the right mode for the circumstances will bring you an actual benefit. And I do hope that Aptera makes it possible for drivers to select their level of regen on the go as more and more EVs are getting this capability. Hyundai/Kia were the first I think, but now we also see them for example with VAG cars.

[JRWiley]

Viewing one of the Aptera videos, we were shown on the control screen that using full regen would increase range. Would it be the case that if I were driving in free flowing traffic on a highway with no regen I could actually gain even better range? Does the no regen mode have the feel of an ice car being put in neutral?

[hans-roes]

Without seeing any explenation from Aptera where they get those numbers from or how the behavior of the car changes, it’s difficult to say where it comes from. If, for example, the physical brakes engage from the moment you press the brake pedal and therefore use less regen, then it is correct that enabling regen could offer you more range. And it is possible that an average driver, who does not like to change the setting, will benefit more from having it turned on than off.

But as has been shown multiple times already, driving with regen on is not always the best option. A couple of years ago, when I was slowly getting more and more into EVs, I came across a video on YouTube about the just launched LEAF 2.zero. Nissan had invited a bunch of press and influencers to a nice and warm location (can’t remember where) and at one point gave them a challenge. Drive down from the mountain to a town and they added a small contest to it. Winner would be the person with the lowest consumption. 2 teams arrived with equal consumption Bjorn, if it was him, had done the run with regen off, the car in D-mode, no e-Pedal, no AC, …

[kerbe2705]

Yes – coasting without regen feels exactly like coasting in neutral.

[john-malcom]

Regen is one of the features of EVs that us older ICE drivers need to adjust to. The Aptera engineers have provided the opportunity to select various levels of regen to suit our preferences based on our driving circumstances. We have the opportunity to experiment to find the right settings or to select a setting and adjust to it in all driving conditions.

I think, that as Aptera learns lessons for the Beta prototypes, and subsequent refinements to production, and releases that information to us, we will have a good appreciation to the capabilities and range of regen available in production.

A have a neighbor with a Bolt. He likes the one pedal driving that requires strong regen. I drive a Model3. I like the light regen as I am an old Ice driver and can’t break the ICE driving habit. Maybe I need a 12 Point Program, ICE Drivers Anonymous …..

[trollfaced-hudagmail-com]

less reliance on regen and more reliance on maintaining momentum is better for both efficiency and battery life.

especially for long drives, to prevent user from needing to stay on pedal position to maintain momentum: screen should require pedal to be around a certain position in order for cruise control to be disengaged, or even better a mechanical locker on pedal or electric motor actuating pedal, that way maintaining speed after disengaging is lot easier. mechanical version is like chain and pulleys and a door sliding lock type thing.

[george-hughes]

The regen you get when cruising, whether heavy or light, is just a tool you can use to control speed. If you control speed wisely, you can maximize regeneration and often do so using one-pedal driving.

First, heavy regen is useful for driving where there is a lot of acceleration and slowing, as in running through hilly curves on a secondary road or just plugging along in heavy traffic.

Certainly most of us remember driving an ICE car down a long steep hill. In those circumstances, truck drivers often shift to a lower gear to avoid over-heating the brakes.

We all know that it takes energy to go up hill and one of the advantages of an EV is that it will generate energy on the way down which ICE vehicles can’t.

Regen feels like a lower gear going down hill and is strong enough to slow the car when going down hill on most hills.

In the Spark EV I drive, there is negligible difference between high and low regen, as measured by KW generated, when going down mild hills at a speed set by cruise control. When going down steeper hills, the normal regen found in “D” on the Spark, will be overwhelmed by gravity and it will accelerate. However, in “L”, my EV is capable maintaining the speed set in cruise with an increase in the KW generated number on steeper hills.

The instrument display of the Spark allows the display of +/- KW in real time in one of its screen options. This provides a precise instrument to gauge your power use.

For instance there is about a six-mile run from the western part of the county to the center that is largely downhill. Of course it includes up-hill portions but on average, you lose 150-200 ft. of elevation going west to east. I set the car’s cruise at 55 at the first hill crest. The motor is generating at about 4-5 kw as I head to the valley. As I head up the next hill, I limit my kw power to no more than 20 kw. This costs me maybe three mph by the time I hit the crest of the next hill where the decline is significantly larger. I add enough KW (no more than 30kw) to regain my speed which results regen in “L” rising to 20-25KW in following 40-60 seconds of regen. The next rise is relatively mild and I let the cruise maintain 55 mph as the KW output to power the motor remains under 15kw … and so on with adjustments made with the cruise controls.

The point is by the time I’ve reached town, my GOM range has increased 2-3 miles. In another 8 mile run to town on some back roads, I can get the display to report consuming energy at the rate of 6.8 miles/kw using the same technique.

Bottom line, maximizing regen is a ‘game’ you can play provided you have the instrumentation. I do hope the Aptera will have real-time numeric display of power in both acceleration and regeneration. This allows you to gamify driving with hand controls.

The funniest take-away of this ‘game’ is that folks in ICE vehicles – particularly Semi’s – tend to exceed the speed limit down hill to make it easier to get up the next hill.

By my use of gravity to maximize regen, the ICE vehicle driver has to put on the brakes to maintain 55 wasting that energy heat. The funny part is when I maintain 55 uphill they are usually left behind.

Besides the game, I use maximum regen to maximize my one-pedal experience.

[Fran]

Regen is only “more efficient” for those who drive like a normal ICE driver, who maintain speed until they get to a turn or stop and then use their mechanical brakes to slow down or stop. Efficient driving is NOT using the brakes at all, coasting from way out while approaching a turn or stop. Regen brakes are useful for these efficient drivers when a car pulls out in front of you or a traffic light changes while you are approaching at speed and expected to get there before it turns. Regen process is not totally efficient, maybe 90% to turn the kinetic energy into electricity and 80% to put that electricity into the battery. Then to get that energy back to moving the car again, 90% to get electricity out of the battery and 90% the use the motors to get the car moving. If these estimates are correct (they are not) the total efficiency of the whole process is 90% times 80% times 90% times 90% or .9 x .8 x .9 x .9 = .5832 or 58.32%, where if you just coasted and planned your stops so you never used the brakes, the efficiency would remain at around 90%.

[Greek]

I constantly go from drive to neutral if I know I will be stopping or at least slowing down until the next traffic signal…I don’t do it always because I believe switching gears also takes energy away from the battery.

Another thing in terms of efficiency. If you have a somewhat full battery, your regen is not as effective, as it limits the amount of energy it wants to receive to protect the battery. So stopping distances become longer.

[geoff-dale]

I found it did not take long to get used to one pedal driving in a Model 3 on the higher regen setting. Just as you modulate your acceleration you do the same decelerating including coasting. No need to keep changing regen levels or selecting neutral just use your right foot, hardly ever touch the brake . Very satisfying comfortable and economical way to drive!

[JRWiley]

Will different levels of regen be available on the Aptera, and can it be changed while in motion?

[harry-parker]

I can’t image it wouldn’t. Every other EV on the market with selectable regen allows it to be changed on the fly. Even my 10 year old Chevy Volt can do that.

Then again my old Gen 1 Volt does it via the stick shift. Newer Gen 2 Volts use a switch on the steering wheel. The question is, how will Aptera alllow us to change it? How many levels deep in the onscreen menu will we need to go?

[Jeff]

Teslas no longer have adjustable regen settings. Back when they did, you had to go into the settings on the touchscreen to change it, so not something you’d do on the fly like you might with the Chevy Volt controls.

You *can* shift into neutral to coast with zero regen, but I don’t think hardly any drivers actually do that. (I’m the exception.)

If I were a betting man, I’d bet Aptera follows Tesla’s suit and does not provide a way to change the regen settings.

[Sam]

I hope there’s at least Off, Low & High.

[craig-merrow]

The Chevy Bolt EUV that I test drove last year had a paddle behind the steering wheel for regen, although I don’t recall if that worked in conjunction with one pedal driving. The Tesla Model 3 we rented didn’t have any regen adjustments that I’m aware of (we only had it for three days), but the one pedal driving worked very well for us.