Regen question

[broosth]

I see a lot of owners prefer one pedal mode and seem to think it provides more regen. I can't stand the way the car drives in L, so keep it in drive and use the brake pedal as I always have. Since the brake pedal ALSO causes regen,, how can it be less effective than one pedal mode or the regen paddles? If I slow down with regen, how can it matter which way the car is told to regen? I suppose that if I were to brake hard enough to actually engage the brake pads that would be a difference.

 

[trevmar]

I too was skeptical about L, but have adapted to it and I now prefer the way I get "instant" slowdown with using one pedal. Correct me if I'm wrong, but there must be a time delay between "power on" and "braking" when using two pedals, unless you're a rally car driver and brake with your left foot - ?

 

[broosth]

There really is no delay. When my foot comes off the accelerator, the car starts slowing down rather like a car with an automatic tranny or my manual shift with the car still in gear. But the slowdown is not nearly as aggressive as L mode. i drove manual shift for most of the past 50 years and got very good at allowing the car to slow on its own approaching slower traffic or a light. So I tend to brake lightly as needed and I see regen working all the time.

 

[SeanNelson]

Since the brake pedal ALSO causes regen,, how can it be less effective than one pedal mode or the regen paddles? If I slow down with regen, how can it matter which way the car is told to regen? I suppose that if I were to brake hard enough to actually engage the brake pads that would be a difference.

I think that's the biggest issue - in "D" mode you don't know exactly where regen ends and hydraulic braking starts, so it's more likely that you'll waste momentum by slowing too fast. In "L" mode there's no doubt about what's going on - if you're not slowing fast enough and you need to use the brake then you know for sure you're stopping too quickly and you can adjust your driving habits to avoid that.

 

[broosth]

Certainly one way of looking at it. Some drivers insist on driving full speed until the last moment; some of us like to coast up to a red light. Coasting regen's all the way.

 

[BoltEV]

I like to drive on a freeway with Cruise Control set and in “L” especially if the terrain is hilly up and down.

On the downhill, the regen automatically keeps me from exceeding the cruising speed and hence waste energy, while returning energy to the battery.

I do not have to use the brake pedal.

 

[gpsman]

Cruise control works great in D also on hilly terrain.
I love it does not run away or accelerate in the least on downhill sections. I’m in N. Calif. and never had a hill too steep for D.

L is for lots of speed changes.
City with stop lights/signs, or bumper to bumper stop-N-go.

D is for highway when you want GRADUAL speed changes. Like coasting down an off ramp. L is too agressive for high speed use. You’ll piss off those behind you or get rear-ended with a pedal release in L at 65 mph.

And yes, you can regen the same amount in D or L.
It is only a program change in how the car behaves, how rapidly it automatically regens. A human foot can mimic D or L. It’s just another push button. Like “sport” mode.

 

[SeanNelson]

D is for highway when you want GRADUAL speed changes. Like coasting down an off ramp. L is too agressive for high speed use. You’ll piss off those behind you or get rear-ended with a pedal release in L at 65 mph.

I really don't understand comments like this. You can slow down as gradually as you want in "L" mode by just slowly and smoothly easing pressure from the accelerator pedal. There's nothing about "L" mode that makes the regen "all or nothing". If you can press on the brake pedal lightly for a gradual stop, then you can press on the accelerator pedal lightly and stop just as gradually. In fact I can stop even more gradually and smoothly in "L" mode than "D" because I don't have to shift my foot from one pedal to another as the car drops below creeping speed.

 

[iletric]

D is for highway when you want GRADUAL speed changes. Like coasting down an off ramp. L is too aggressive for high speed use.

I do exactly the same thing. And once in town, I switch to L to come to a stop. And if I miscalculated I switch between D and L to make a perfect stop behind the line without touching the brake.

 

[BoltEV]

D is for highway when you want GRADUAL speed changes. Like coasting down an off ramp. L is too agressive for high speed use. You’ll piss off those behind you or get rear-ended with a pedal release in L at 65 mph.

I really don't understand comments like this.

I agree!

I so enjoy one-pedal driving that I have to remember to use both pedals when driving my ICE car!

 

[mojito5606]

I always wonder does the L mode put any strain on the electric motor?

 

[SeanNelson]

I always wonder does the L mode put any strain on the electric motor?

Nope.

 

[GetOffYourGas]

I always wonder does the L mode put any strain on the electric motor?

Nope.

Well, technically yes it does put some strain on the motor. I mean, that is what is slowing down the car after all. But it is far less than normal acceleration. Nothing that's going to add noticeable wear-and-tear.

 

[gpsman]

Anyone ever have regen totally disabled?

I just did for the first time.

Was on a DCFC. Going on a long weekend trip. No one was waiting so I sat there and let it sit to go to 100%. It got to 100%. The car, the my chevy app, and the charger all said 100%. And it kept charging and charging and charging. For 30 minutes more at 6kw.

Usually it tapers fast. Even on a L2 it tapers from 6kw to 1 kw in about 15 minutes and then stops. I figured maybe it was doing cell balancing. It was 60 degrees so no cooling or heating was needed.

The voltage and SOC must have been extra high.
Normally pulling away “fully charged” I get 10 or 15 kw of regen. Enough to cautiously slow you down.
For the first time in 2 years and 25,000 miles I got nothing. When I let up on the pedal it was like coasting in neutral. A very wierd feeling for this car.

The icon was grey as usual, but the white line that moves was stacked on top of the other white line. After about 2 miles / 3 minutes the white line started moving down. This DCFC was also putting in 47 kw for an unusually long time also. Normally I don’t see more than 45 kw and maybe a flicker of 46 kw for a few seconds, but it PARKED at 47 kw for like 15 or 20 minutes. I wonder if the line voltage at the DCFC was a little higher than usual. Like some L2 are as low as 205 volts, 208 volts is average, 220 volts sometimes, 240 volts ocassionally, and 250 volts possibly. (The Bolt L2 can accept up to 266 volts without harm.)

 

[SeanNelson]

Yes - when you do a fast charge it takes 10 to 15 minutes to balance the cells (or whatever it's doing) after the display hits 100%. The battery management system deals with this, it doesn't matter what the voltage is (and in fact with a DC fast charger the car controls the voltage coming out of the charger). The long period of time at 100% is just a quirk of fast charging.

And yes, with a 100% charge you'll get little to no regen. It's usually a bit startling the first time you lift your foot off the "go" pedal but after that you just deal with it until you get some room in the battery.

 

[NeilBlanchard]

I would love it, if we had a way to coast when you lift your right foot! As it is now, I put it in N when I need to coast, but this is not as easy as just lifting your foot - and you have to put it back in D to get any regen, even on the brake pedal.

I like regen - but only when I want to slow down. I hope that GM gives us an option to have no regen on the accelerator pedal in D.

 

[SeanNelson]

I would love it, if we had a way to coast when you lift your right foot! As it is now, I put it in N when I need to coast, but this is not as easy as just lifting your foot - and you have to put it back in D to get any regen, even on the brake pedal.

I drive in "L" all the time - when I want to coast I just release pressure on the accelerator pedal to the point where my speed remains constant. Seems to work fine for me.

 

[GetOffYourGas]

I'm with Neil here. When driving hundreds of miles, feathering the accelerator gets tiring.

 

[SeanNelson]

I'm with Neil here. When driving hundreds of miles, feathering the accelerator gets tiring.

Just hasn't been an issue for me. I had problems with doing it in my Prius C because the accelerator pedal had such a feather-light touch that maintaining a certain position was like holding my foot suspended in the air. But the Bolt has a healthier return spring, and I find that I can maintain pressure on the pedal for hours without any problems.

On long, relatively straight stretches (which tend to be the exception rather than the rule here in mountainous British Columbia) I tend to use cruise control if the traffic isn't too heavy. But I guess I'm never really in situations which require coasting for such a long time that using the pedal to control it is a problem. Coasting for a distance means going downhill, and I find that usually either means cruise control or having to slow down for curves pretty frequently.

 

[GetOffYourGas]

But I guess I'm never really in situations which require coasting for such a long time that using the pedal to control it is a problem. Coasting for a distance means going downhill, and I find that usually either means cruise control or having to slow down for curves pretty frequently.

I think this sums up the difference in our experiences. In the northeast, having long gradual downhill sections is fairly common, especially on highways like I-90.

Still, it wouldn't hurt you if freewheeling was available as an option. You don't have to use it if you don't like it.