Regen Braking Question - do it easy or hard?

[spokey]

I don't see this discussed anywhere and have been curious as to what is the most efficient regenerative braking.

For reference I have I have a 2020 MY LR. And I'm thinking of regen on 'standard'

It seems that even if there isn't much difference that there is some difference between a light regen braking and a heavy braking.

What I mean by light and heavy is

Heavy - I'm coming up to a stop and know when to just take my foot off the pedal and allow the car to stop as fast as it can coming to a complete stop right at the stop line.

Light - Same thing but I start a lot further out and lift my foot just slightly to slowly decelerate to and stoppng right at the stop line (perhaps pissing off the drivers behind me of course)

Maybe the heavy is worse due to a bit of heat buildup?

 

[sleepydoc]

Light regen will be better for 2 reasons. First, you use more of the intrinsic rolling resistance of the car for braking. Second, there is power wasted in charging the battery. Nominally, power is proportional to current squared. Harder regeneration means more current and more power wasted energy.

 

[spokey]

Light is what I've speculated and usually do. It did occur to me that the regen process might utilize stuff that also takes energy and the time spent would make a difference. But then of course I think you're referring to heat waste which I also considered.

 

[archae86]

There is another consideration--energy loss to air resistance. This is strongly higher at higher speeds, so getting your car slowed down from at least the top part of your cruising speed as soon as consideration of traffic makes it prudent once you can see the stop light or other situation is going to make you stop is helpful for economy.

Not that the battery captures all of the energy you take off by regen, but it gets most of it. It gets none of the energy you lose to air resistance.

I'm annoyed that FSD Beta in the current release waits much longer to begin slowing down than I would driving manually--which I am confident is a bit of a hit on range.

 

[spokey]

hmm. Didn't think of that. So maybe (assuming traffic will bear it) do a moderately quick slowdown. Say 60 to 35/40 and then slowly coast in to the light or stop sign

 

[sleepydoc]

I'm annoyed that FSD Beta in the current release waits much longer to begin slowing down than I would driving manually--which I am confident is a bit of a hit on range.

Yeah, a lot of people have commented how FSD tends to wait until the last minute to brake and at times even accelerate up to red lights. Not the safest or most efficient way to drive. Hopefully that gets tweaked in subsequent releases.

hmm. Didn't think of that. So maybe (assuming traffic will bear it) do a moderately quick slowdown. Say 60 to 35/40 and then slowly coast in to the light or stop sign

Wind resistance is like rolling resistance. The car is always working to overcome it. The most efficient braking would probably be to have zero regeneration and simply let the intrinsic resistances slow the car down to zero but traffic won’t allow that. At higher speeds you will have a larger braking effect due to wind resistance. It will be pretty negligible below 30-40 MPH, though.

I think you’re really overthinking this, though. Brake early and gently within reason but don’t go nuts; just drive the car!

 

[spokey]

Oh yeah probably overthinking but it's mostly an interesting mental exercise. Part of the get the lowest watts per mile game. Like hyper-miling with an ICE.