Regenerative Braking Drive Modes Gimmicky?

[SDegolf]

I feel the Regenerative Braking Drive Modes are gimmicky. I understand it is supposed to charge your battery more, but it comes at the price of losing the ability to coast. Putting in B mode is similar to driving a stick car in 1st gear only. When you let your foot off the gas, the car will slow down a lot more in order to charge your battery, but in the end you lose the distance that you would have covered by coasting in D. If I am driving 65MPH on the freeway and set it to D and let my foot off the gas, I can continue to coast for quite some time. However, if I set it to B and let my foot off the gas, the car will slow down and eventually stop. How is that beneficial for efficiency?

Can someone chime in with their experience? Do you really gain mileage by doing this? Thanks.

 

[miimura]

When I'm in town naturally accelerating and decelerating with lights, stop signs, traffic, etc., I use D2. This feels natural to me and with some looking ahead for when I need to slow down, I rarely have to touch the brakes except to finally come to a complete stop. Of course, on the freeway you want to coast as much as possible, but when there's a lot of traffic I still find D2 to be useful. You just have to modulate the accelerator pedal a lot more than you would with a ICE vehicle. The benefit is that you have to move your foot to the brake pedal a lot less. You also have to realize that the first part of the brake pedal in the e-Golf also regenerates instead of using the friction brakes. So, if you only use D (with no accel pedal regen) and brake lightly (decelerating at exactly the same rate as the other D levels or B), you get the same efficiency result from regen energy recovery.

So, no, it's not gimmicky at all to me and the fact that it lets you set several different levels is unique in the EV market and very much appreciated by me. You just have to break the habit of using the accelerator like an on/off switch.

 

[JoulesThief]

If you don't like it, don't use it... end of gimmick. I drive around in D mode all the time. If I want to slow down, I have two choices, use the shifter like a stick shift model to shift into "B" mode, or step on the brake pedal. I am used to shifting a manual, it's no big deal.

The features were built in for those that don't feel it's "gimmicky" and know how to use the features to their fullest advantage.

Yes, if used properly, and you e brake far enough in advance, so you don't need to step on the brake pedal, it does increase efficiency due to regenerative brake recharging.

 

[forbin404]

Don't forget that when you are driving in B and you take your foot of the pedal, some of that energy is 'regenerated' into your battery. So you WILL slow down. Energy doesn't just come out of thin air, making energy means something else is lost.

B mode is best in heavy city driving, it saves on the brake, and gives you an extra few miles to your meter.

 

[cctop]

I agree that D2 feels most natural compared to ICE cars. I'd use it more often if I didn't have to keep resetting it to D2 every time I got in the car.

I love being in B mode as I commute up and down the hills of San Francisco. It's basically one-pedal driving. It's so intuitive that I very nearly got in an accident in my wife's car when, approaching a stoplight, I absent-mindedly tried to tap the shifter south to B mode instead of braking.

But B mode is not fun for passengers in the car. Ever ridden with someone who is heavy on the gas and the brake? A big reason why I didn't get the BMW i3 is that it's only driving mode is similar to the eGolf's B mode.

SDegolf -- regarding your question of whether B mode is really more efficient, it gives me about 20% better mileage for my 8-mile commute across SF.

 

[Verkehr]

Driving in any mode with the power meter at "12:00" is effectively the same as coasting. It seems like there's a little bit of a programmed dead zone in the pedal travel to make this easier to do. My first electric test drive was an i3 which sold me on the one pedal concept.


Here's how I see it:

Benefits of braking mode:
less moving your right foot from pedal to pedal - lazy factor
faster slowing in emergency stop - already at full regen before your foot touches the brake
finer accel/decel control as it's more intuitive to use one pedal

costs of braking mode:
requires driver adjustment from years of driving automatic transmission ICEVs. Easier if you drove a manual gearbox with engine braking IMHO...
requires more concentration to keep foot in the right spot
potentially encourages unnecessary accel then regen to close a gap, wasting power in the efficiency loss of regen compared with closing the gap slowly

 

[RonDawg]

My previous car was a 2012 Nissan Leaf, and it had no "B" mode (this was not added until 2013). In "Eco" mode it didn't provide nearly as much regen as later "B" mode cars.

So, not a gimmick. I live in a hilly area and B mode helps save my brakes. On the freeway I switch to D mode, occasionally invoking D1 for slight downgrades. I never use D2 or D3, if I need that much regen I just go straight to B and depress the accelerator a bit more.

As mentioned already, in B mode it's possible to control the amount of regen via your right foot.

 

[SDegolf]

Awesome. Thanks for the replies!

 

[alexecar]

Hi,

There seems to be disagreement in this thread if the B mode saves more energy than D. I have a simple question: If I decelerate the exact same rate in each mode, either by easing off the "gas" pedal in B vs gently pressing the brake pedal in D, is there the same amount of regen?

I started driving in B mode almost exclusively when I got the eGolf, but lately I have come to appreciate D again as I don't like the added tension in the pedal while coasting on the freeway. I also don't like that you don't have clear control when your brake lights go off, you can scare the people behind you through subtle changes in your coasting.

Regards,
Alex

 

[forbin404]

Hi,

There seems to be disagreement in this thread if the B mode saves more energy than D. I have a simple question: If I decelerate the exact same rate in each mode, either by easing off the "gas" pedal in B vs gently pressing the brake pedal in D, is there the same amount of regen?

I started driving in B mode almost exclusively when I got the eGolf, but lately I have come to appreciate D again as I don't like the added tension in the pedal while coasting on the freeway. I also don't like that you don't have clear control when your brake lights go off, you can scare the people behind you through subtle changes in your coasting.

Regards,
Alex

1. pressing the brake doesn't generate any kind of regen.
2. If you scare the person behind you, they are too close anyhow
3. If you don't like B, try D2 or D3, it isn't as rough.

 

[JoulesThief]

Hi,

There seems to be disagreement in this thread if the B mode saves more energy than D. I have a simple question: If I decelerate the exact same rate in each mode, either by easing off the "gas" pedal in B vs gently pressing the brake pedal in D, is there the same amount of regen?

I started driving in B mode almost exclusively when I got the eGolf, but lately I have come to appreciate D again as I don't like the added tension in the pedal while coasting on the freeway. I also don't like that you don't have clear control when your brake lights go off, you can scare the people behind you through subtle changes in your coasting.

Regards,
Alex

1. pressing the brake doesn't generate any kind of regen.
2. If you scare the person behind you, they are too close anyhow
3. If you don't like B, try D2 or D3, it isn't as rough.

In "D" , take another look at your left gauge while pressing the brake down, gently, in motion, with less than a full charge, then tell us if the needle goes into the green. If your's doesn't go into the green, there's something wrong with your car.

 

[SDegolf]

Just saw this thread:
http://forums.vwvortex.com/showthread.php?7115802-Driving-in-B-mode-all-the-time

 

[alexecar]

1. pressing the brake doesn't generate any kind of regen.
.

If this is the case, then the displays are absolutely misleading. The power display goes into the green regen section for braking in D, and the Power Flow display also shows regen back to battery in this case.

I just did a quick street test. I drove 30mph on a straight empty city street and took my foot off the accelerator in B mode. The power display went to 1 unit regen(first white line in green section), and it took about 4 sec to get the car down to 20mph. Then I switched to D and went back to 30mph. Now I tapped the brake pedal enough for the power display also to go to the 1st line in green regen. It also took about 4 sec to get the car down to 20mph. This is no scientific measurement, and B felt slightly more efficient. It would be good to get clarity.

Regards,
Alex

 

[NeilBlanchard]

Pressing the brakes does do regenerative braking as much as possible, and then it transitions to the friction brakes.

Driving in D is going to be more efficient, because coasting is the most efficient. You will accelerate less, then coast and then use regen if you need to slow down. VW designed it this way for a reason.

I have been ecodriving for over 8 years, and everybody I know who also does this (aka hypermiling) concurs. Wayne Gerdes - who coined the word hypermiling, and everybody on EcoModder do this all the time. The e-Golf is the best car I know of for ecodriving, because it defaults to coasting.

 

[JoulesThief]

Pressing the brakes does do regenerative braking as much as possible, and then it transitions to the friction brakes.

Driving in D is going to be more efficient, because coasting is the most efficient. You will accelerate less, then coast and then use regen if you need to slow down. VW designed it this way for a reason.

I have been ecodriving for over 8 years, and everybody I know who also does this (aka hypermiling) concurs. Wayne Gerdes - who coined the word hypermiling, and everybody on EcoModder do this all the time. The e-Golf is the best car I know of for ecodriving, because it defaults to coasting.

Agreed, if you can read slight changes in elevation and know when you can coast going down hill, you can extend range considerably by taking your foot off the accelerator.

 

[MLS]

Pressing the brakes does do regenerative braking as much as possible, and then it transitions to the friction brakes.

Driving in D is going to be more efficient, because coasting is the most efficient. You will accelerate less, then coast and then use regen if you need to slow down. VW designed it this way for a reason.

I have been ecodriving for over 8 years, and everybody I know who also does this (aka hypermiling) concurs. Wayne Gerdes - who coined the word hypermiling, and everybody on EcoModder do this all the time. The e-Golf is the best car I know of for ecodriving, because it defaults to coasting.

I agree with this. The e-Golf manual even indicates coasting as the most efficient method of driving. I had been driving in B mode for a month, then switched to driving in D. My efficiency increased noticeably.

 

[forbin404]

Pressing the brakes does do regenerative braking as much as possible, and then it transitions to the friction brakes.

Driving in D is going to be more efficient, because coasting is the most efficient. You will accelerate less, then coast and then use regen if you need to slow down. VW designed it this way for a reason.

I have been ecodriving for over 8 years, and everybody I know who also does this (aka hypermiling) concurs. Wayne Gerdes - who coined the word hypermiling, and everybody on EcoModder do this all the time. The e-Golf is the best car I know of for ecodriving, because it defaults to coasting.

I agree with this. The e-Golf manual even indicates coasting as the most efficient method of driving. I had been driving in B mode for a month, then switched to driving in D. My efficiency increased noticeably.

But 'NOW' you are burning the brakes more. Which is cheaper? The savings in Charging or the cost to replace a set of brakes?

 

[RonDawg]

Pressing the brakes does do regenerative braking as much as possible, and then it transitions to the friction brakes.

Driving in D is going to be more efficient, because coasting is the most efficient. You will accelerate less, then coast and then use regen if you need to slow down. VW designed it this way for a reason.

I have been ecodriving for over 8 years, and everybody I know who also does this (aka hypermiling) concurs. Wayne Gerdes - who coined the word hypermiling, and everybody on EcoModder do this all the time. The e-Golf is the best car I know of for ecodriving, because it defaults to coasting.

I agree with this. The e-Golf manual even indicates coasting as the most efficient method of driving. I had been driving in B mode for a month, then switched to driving in D. My efficiency increased noticeably.

But 'NOW' you are burning the brakes more. Which is cheaper? The savings in Charging or the cost to replace a set of brakes?

As Neil mentioned, the way BEV's and hybrids are set up, pressing the brake pedal is supposed to use up regen first. The friction pads are supposed to be invoked only if the desired stopping force is more than the available regen.

There are folks with high-mileage Prii who have never replaced their brake pads.

 

[JoulesThief]

Hi,

There seems to be disagreement in this thread if the B mode saves more energy than D. I have a simple question: If I decelerate the exact same rate in each mode, either by easing off the "gas" pedal in B vs gently pressing the brake pedal in D, is there the same amount of regen?

I started driving in B mode almost exclusively when I got the eGolf, but lately I have come to appreciate D again as I don't like the added tension in the pedal while coasting on the freeway. I also don't like that you don't have clear control when your brake lights go off, you can scare the people behind you through subtle changes in your coasting.

Regards,
Alex

1. pressing the brake doesn't generate any kind of regen.
2. If you scare the person behind you, they are too close anyhow
3. If you don't like B, try D2 or D3, it isn't as rough.

Statement 1, likes some of your other posts, is incorrect and false.

 

[forbin404]

[
But 'NOW' you are burning the brakes more. Which is cheaper? The savings in Charging or the cost to replace a set of brakes?

As Neil mentioned, the way BEV's and hybrids are set up, pressing the brake pedal is supposed to use up regen first. The friction pads are supposed to be invoked only if the desired stopping force is more than the available regen.

There are folks with high-mileage Prii who have never replaced their brake pads.

Actually I was comparing running in 'B' mode vs coasting and using your own judgement to brake smoothly.
The computer can easily decide to run the car down without invoking the brakes often, but can the human?

But even that in mind, I'm a city driver. LOTS of stop / go. (Very little freeway unfortunately). So I believe it would be better for me to let the car regen the energy instead of always using the brake.