Improved Regen Braking

[surfrasch]

Absolutely. For every instance your car is using regen, it is one less instance you are using brakes. Also, when using brakes, you are using less brakes as the load is shared by the regen.

thanks.....trying to understand maintenance requirements.....I heard brake fluid at 25k, battery cooling fluid at 50k.....then what’s left? Brake/tire/wipers wear and tear.....what am I missing?

Guess I’m hijacking the thread a bit, sorry.....

 

[novox77]

My experience is that a commute with lots of regen opportunity (bad traffic) is way more efficient than the same commute going over 40mph. So while recovering regen energy is a lossy process, wind resistance is even lossier, and gets exponentially worse the faster you go. However, these scenarios are usually out of your control. You're regenning a lot because traffic patterns demand it, which luckily gets you better efficiency than if the roads were clear. You do lose time as a result though.

If you're driving on a road with lots of rolling hills, it's better to float the accelerator to find "neutral" rather than try to hold constant speed down the hills and leverage regen. Preserving momentum will be more efficient than recovering regen energy. Do this to the extent that it's safe; you don't really want to be shooting down hills to 60mph in a 40mph zone for example.

 

[insaneoctane]

I read that this is only for RWD varients?

 

[G78M3]

Well said. Or to put it differently: if you find yourself using the brakes often because you find the current regen does not stop you fast enough, then the update will likely help you.

The more that you use regen, the worse mileage that you will get. Regen is better than braking, but transfering energy from the battery to the kinetic energy of the car, and then trying to recover that energy through regen is a very lossy process.

Now if you are doing a lot of hard braking, improved regen might recover a bit more energy and give you a bit more mileage. But I wouldn’t expect a huge improvement.

 

[SteveG3]

[snip...]

If you're driving on a road with lots of rolling hills, it's better to float the accelerator to find "neutral" rather than try to hold constant speed down the hills and leverage regen. Preserving momentum will be more efficient than recovering regen energy. Do this to the extent that it's safe; you don't really want to be shooting down hills to 60mph in a 40mph zone for example.

not sure what you meant by that first part... how is that done? I may be mistaken, but, I got the impression some people put the car in neutral, though I don't know how that's done. Re safety, yeah, fair point... I'd only look to do this on fairly empty highway stretches. My efficiency focus is mostly on highway drives of hundreds of miles, so most of it away from congested urban/suburban sprawl.

 

[SteveG3]

Stronger regrn would only be more efficient if you are otherwise forced to use friction brakes. For typical cruising, stronger regen would have no effect. For driving with frequent stops, again where the friction brake would otherwise be used, then the stronger regen will likely yield a very minor improvement.

Perhaps the ACC of AP rarely if at all uses the friction brakes on the kinds of hills I generally see on long highway drives.

At this point, the discussion has got me expecting very modest to no improvement on this kind of highway cruising... looking forward to the OTA coming, as, if nothing else, will be a nice plus for driving in traffic.

 

[VT_EE]

Don’t have my 3 yet and still learning, but does the regen extend the life of your brakes considerably?

Your brake pads will rust off before needing replacement. Mine are very minimally used.

 

[novox77]

Perhaps the ACC of AP rarely if at all uses the friction brakes on the kinds of hills I generally see on long highway drives.

At this point, the discussion has got me expecting very modest to no improvement on this kind of highway cruising... looking forward to the OTA coming, as, if nothing else, will be a nice plus for driving in traffic.

the spot in the throttle where there is no power consumption and no regen is a fixed point on the accelerator. That's pretty much neutral. Def don't recommend using the stalk to go into neutral. You're right; highway driving without traffic, you're pretty much at the mercy of wind resistance, so if you're looking for efficiency, keep it at 65mph and optionally tail a semi safely

 

[SteveG3]

the spot in the throttle where there is no power consumption and no regen is a fixed point on the accelerator. That's pretty much neutral. Def don't recommend using the stalk to go into neutral. You're right; highway driving without traffic, you're pretty much at the mercy of wind resistance, so if you're looking for efficiency, keep it at 65mph and optionally tail a semi safely

appreciate your trying to help me understand how to do that... still not sure I understand... do you just mean it is easy to maintain a level of pressure on the accelerator pedal at which you can easily see on that line on the screen no regen or consumption? and/or is there actually some sort of stickiness to a position in the travel of the accelerator pedal?

 

[novox77]

appreciate your trying to help me understand how to do that... still not sure I understand... do you just mean it is easy to maintain a level of pressure on the accelerator pedal at which you can easily see on that line on the screen no regen or consumption? and/or is there actually some sort of stickiness to a position in the travel of the accelerator pedal?

There's no tactile feedback on the pedal. Just use the throttle/regen bar. When there is no bar in either direction, you've found "neutral." That point is fixed in the accelerator, so if you keep your foot in place, you'll essentially be coasting.

 

[kbecks13]

There's no tactile feedback on the pedal.

The best tactile feedback is your butt in the seat feeling the acceleration

 

[Uncle Paul]

With 310 of nominal range, drafting behind a semi or shifting into neutral should not become a factor, unless it is a game you are playing to get the highest number possible, or poor judgement on selecting charging strategy.

 

[Accentcreate]

As I live in a mountainous region of Europe, the Pyrenees, I would certainly prefer more regen options and the ability to coast on long hills. Both the Standard and Low regen are too strong when descending a long, winding road as both slow the car to a crawl, requiring the use of the accelerator and (one assumes) battery power to keep the car moving.

In my old ICE vehicles I typically descend 30 or more kilometres without touching the accelerator or brakes (unless there are flat spots or dips). By working through the gears it is easy to make a complete descent using only the clutch and shifter.

Surely this should be easy to achieve with a software tweak, using the steering wheel buttons or one of the paddles. Perhaps selecting "Mountain Mode" on the screen then working through different levels of regen to maintain momentum and keep the batteries charging throughout. Come on Elon, shouldn't be too hard.

Obviously you'd be limited if you started with a full battery, but I've not yet found a charger at the top of a mountain.

 

[TT97]

As I live in a mountainous region of Europe, the Pyrenees, I would certainly prefer more regen options and the ability to coast on long hills. Both the Standard and Low regen are too strong when descending a long, winding road as both slow the car to a crawl, requiring the use of the accelerator and (one assumes) battery power to keep the car moving.

When traveling downhill, even if you need to use the accelerator, the car can still regen. Next time going down a hill, take a look at the power bar, it will still be green if you are pressing the accelerator.

 

[DBeckwith]

Pressing the accelerator in your situation does not use battery but only reduces regen. Use Traffic Aware Cruise Control (TACC) and let the car modulate it for you.

 

[VT_EE]

Umm, the accelerator pedal does not work the same as in an ICE. Coasting actually requires some amount of pedal pressure unless you are going down an incredibly steep hill. It’s like driving a golf cart. As people above noted, look at the power bar if you really want to know whether you’re putting in or taking out power.

 

[Accentcreate]

When traveling downhill, even if you need to use the accelerator, the car can still regen. Next time going down a hill, take a look at the power bar, it will still be green if you are pressing the accelerator.

I think my eyes will be on the road, thanks.

 

[G78M3]

The easiest way to accomplish this: Set cruise control to your desired speed. The car will reduce regeneration (but still regenerate) to maintain the desired speed. If you want to do it yourself, simply modulate the acceleration as needed to maintain speed. Same effect: the car will not use additional energy, simple will regenerate a bit less to maintain speed.

For more advanced users, your suggestion makes sense, ideally we could set the desired regen from zero (coasting) to maximum, instead of the current two options (chill and max). The problem with this is that the vast majority of users won't fully understand, and will be tempted to set to coasting mode as it is what they are used to with ICEs, and in doing so, they will get less range (and blame EV technology for it).

 

[Accentcreate]

The easiest way to accomplish this: Set cruise control to your desired speed. The car will reduce regeneration (but still regenerate) to maintain the desired speed. If you want to do it yourself, simply modulate the acceleration as needed to maintain speed. Same effect: the car will not use additional energy, simple will regenerate a bit less to maintain speed.

For more advanced users, your suggestion makes sense, ideally we could set the desired regen from zero (coasting) to maximum, instead of the current two options (chill and max). The problem with this is that the vast majority of users won't fully understand, and will be tempted to set to coasting mode as it is what they are used to with ICEs, and in doing so, they will get less range (and blame EV technology for it).

Interesting, re chill and max. In European English our settings are Standard and Low, with Standard being the stronger regen. I'll give your cruise control idea a try next time I do a decent descent. But would love an "advanced users" option as I love to push the envelope when descending.

 

[G78M3]

Interesting, re chill and max. In European English our settings are Standard and Low, with Standard being the stronger regen. I'll give your cruise control idea a try next time I do a decent descent. But would love an "advanced users" option as I love to push the envelope when descending.

Same here, std and low. Chill is for acceleration, not sure what I was thinking...