Yogi62
Posts: 169
Joined: Sat Jan 12, 2013 7:29 pm
Delivery Date: 13 Apr 2013
Leaf Number: 405771
Location: Boston

Re: Regenerative braking - why have the option to NOT have this?

Thu Nov 19, 2015 6:12 pm

I always have ECO on (for easier pedal modulation and lower heater power usage) and 90% of the time I use B.

The two times I want D mode (or less):

1. On the highway when I want the regen to not kick in so fast in cruise control.

2. When driving in snow, sleet. I really don't want regen to kick in and out as it senses the surface.

jpadc
Posts: 269
Joined: Sat Dec 13, 2014 7:25 am
Delivery Date: 20 Dec 2014
Location: Indiana & Wisconsin

Re: Regenerative braking - why have the option to NOT have this?

Thu Nov 19, 2015 7:39 pm

EVDRIVER wrote:Nissan needs to really change their product to win in the new landscape or even survive


http://cleantechnica.com/2015/03/28/ev- ... 000-units/
2013 Leaf S /w Charge Package - Purchased new in Iowa City Dec. 2014
My previous car was a 2008 Prius Touring Package 5 - 73k Miles, 43 MPG lifetime

knightmb
Posts: 420
Joined: Mon Jan 12, 2015 7:41 pm
Delivery Date: 15 Sep 2013
Leaf Number: 414897
Location: Franklin, TN

Re: Regenerative braking - why have the option to NOT have this?

Thu Nov 19, 2015 10:24 pm

dthwaite wrote:I think it would be simpler to always have maximum regenerative braking and just have the "eco" mode to dampen acceleration/limit aircon as it does. With "b mode" you get two levels of regen which is extra superfluous.

I find it tedious always to select "b mode" (its not the default) and I also find it disconcerting that the regen is significantly lessened when the battery is full, so my driving experience is materially altered for no good reason (hey, why's the car not slowing down? oh, battery full).

You can always reduce/control the regen braking effect by keeping your foot lightly on the accelerator. I also think the regen slowing is more similar to engine braking in cylinder cars .

The only reason I can think of having no (or less) regen is perhaps there being some regulatory requirement that lifting your foot of the accelerator pedal should not induce too much braking? Or maybe the brake lights don't go on in max regen mode? But I should think they would go on triggered by the rate of deceleration rather than by what means was used to slow the car.

What do others think?

While I agree, having a "no-regen" mode would be helpful in non-traffic/country driving to save energy, the current D mode only does 10kW of regen and unless you are rolling uphill or against a head-wind, takes a very long time to bring the vehicle to a near stop. My wife's automatic transmission car has twice the engine braking that the Leaf does in D mode so I've always thought that D mode regen was just very weak to begin with. In usual up or down hill driving or traffic, you find yourself using the brake a lot to control speed. I don't know if I would want the vehicle to truly coast all the time (no-regen) to save a very small percentage of energy in the long run. On the flip side, the B mode has a lot more stopping power than my wife's car, so I can almost drive with a single pedal around town, actually saves a lot of accelerator and brake swapping with the foot.

Driving the vehicle at 100% charge is basically no-regen mode for a couple of miles and it does take a little time to get the correct mind-set that if I let off the pedal, I will keep rolling pretty darn fast. But I've never had any problems with the brakes and my mind only takes a short amount of time to adjust my driving accordingly to the change until the battery is finally depleted enough to create a better braking effect.

With that said, I think what the Leaf has, currently, is about the best "one size fits all" that they could do for non-technical drivers. I live in an area where I pass a hundred other Leaf vehicles every day and most of the people that I talk to that own a Leaf just drive it like a car, never touch Eco mode or B mode on the vehicle and many don't even know what they do. So it is easy for us, the very technical and knowledgeable Leaf owners to criticize the choices for regen in the Leaf, but I think Nissan is probably trying to cater to the masses on this.

NeilBlanchard
Posts: 588
Joined: Sat Oct 11, 2014 5:02 pm
Delivery Date: 14 Oct 2014
Leaf Number: 306278

Re: Regenerative braking - why have the option to NOT have this?

Mon Nov 23, 2015 8:12 pm

I much prefer the regen arrangement on the e-Golf: free wheel coasting in D, regen on the brake pedal, and 4 levels of regen available on the shifter D1, D2, D3 and B in increasing order.

Coasting is by far the most efficient way to move the car, and making this easy means that you accelerate less, and then you use regen less, too. Regen is only used when you have to slow down, instead of friction brakes.

To do this in the Leaf, I have to shift into neutral. Which is easy enough, but the e-Golf is easier still - and to go again, you don't need to put it back into D.

User avatar
Jefe
Gold Member
Posts: 137
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Delivery Date: 28 Nov 2015
Leaf Number: 405983
Location: Raleigh, NC

Re: Regenerative braking - why have the option to NOT have this?

Thu Dec 03, 2015 7:52 am

finman100 wrote:Hmmm, excess regen generates heat you say? big ol resistor? i'd say we have another cold-weather package to sell! Take that heated resistor and force the hot air into the cab for all those in winter climates. Heck, even i'd like some of that for defog purposes up here in the PNW. Go fast, then brake to 'over-regenerate', thus creating defog/heat for the cab. win-win.


For some reason this reminds me of The Martian. Have you read it?
2013 SV + Premium Pkg. No QC.

finman100
Posts: 271
Joined: Thu Sep 20, 2012 10:42 am
Delivery Date: 06 Jun 2014
Location: Albany, OR

Re: Regenerative braking - why have the option to NOT have this?

Thu Dec 03, 2015 9:40 am

Seen the movie.
I imagine the book has many different details than the movie did? I'll have to find a copy since I liked the movie.
Albany, Oregon
2014 Silver SV with charge/LED package. June 2014, I'm in the EV game!
40,200 miles
18.5 kWh on 100% charge (54-ish Ah)
4.2 miles/kWh average
Best trip: all of 'em. They're all no-gas!

WyrTwister
Posts: 89
Joined: Tue Jun 21, 2016 2:34 am
Delivery Date: 27 Jun 2016

Re: Regenerative braking - why have the option to NOT have this?

Tue Jun 28, 2016 5:12 pm

Nubo wrote:
garsh wrote:I've said before that I'd like to add a big-old resister. Whenever the battery is too full, shunt the regenerated power to the resistor. That way you always have full regenerative braking available, and the brake performance can always be the same, instead of having diminished regenerative braking when the battery is full.

But that's an extra expense, and you have to figure out how to safely dissipate the generated heat.


These guys will hook you up. :lol:

http://www.mosebachresistors.com/resistors_rl.html

To OP, you can't just dump energy into the battery when it's full. That would result in disastrous overcharging of the cells. The alternative is as garsh suggested, a "big ol' resistor". That is what diesel-electric locomotives use. REALLY big ones. Converts the excess electricity into LOTS of heat.






I think , at one time , subway cars used a bigmresistor bank , too ?

God bless
Wyr

wuyan
Posts: 1
Joined: Wed Jan 07, 2015 3:19 pm
Delivery Date: 26 Jun 2015
Location: Beijing,China

Re: Regenerative braking - why have the option to NOT have this?

Tue Jul 26, 2016 2:19 am

dthwaite wrote:I think it would be simpler to always have maximum regenerative braking and just have the "eco" mode to dampen acceleration/limit aircon as it does. With "b mode" you get two levels of regen which is extra superfluous.

I find it tedious always to select "b mode" (its not the default) and I also find it disconcerting that the regen is significantly lessened when the battery is full, so my driving experience is materially altered for no good reason (hey, why's the car not slowing down? oh, battery full).

You can always reduce/control the regen braking effect by keeping your foot lightly on the accelerator. I also think the regen slowing is more similar to engine braking in cylinder cars .

The only reason I can think of having no (or less) regen is perhaps there being some regulatory requirement that lifting your foot of the accelerator pedal should not induce too much braking? Or maybe the brake lights don't go on in max regen mode? But I should think they would go on triggered by the rate of deceleration rather than by what means was used to slow the car.

What do others think?


Dear OP:
This is my very first post.
I brought LEAF (Chinese version Venucia e30) one year ago.
We don't have the ECO button on the steering wheel instead on the shifter we have "D" and "ECO" mode.
Our "ECO" mode = Your "ECO"+"B"
Our "D" mode = Your "Non ECO"+"D"
And yes the car remember your last choice.

I agree there are drives have no clue what "ECO","None ECO","D","B" means (I personally know people driving this car for month without knowing there is a "ECO" mode).

I personally love your "B" mode, but I hate "ECO" slow down the paddle response make the car feel less agile and nimble(And there is no cruise control option in China).

So I order the steering wheel button assembly from Japan and a cruise control module for Nissan ICE car.
Image
Retrofitting on my car:
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It's true for a experienced driver if you turn off or dail down break regen you have more mileage.
Especially on the high way if you drive downhill coasting change POTENTIAL energy to KINETIC (height -> speed) is much more efficient then charging your battery (efficiency < 40%).

According to the LEAF service manual:
Leaf is capable of 80kw of out put and 24kw of break regen.
On the power meter of the instrument panel:
Each dot on the right side(Power Output) represent 8kw of energy (10 dots in total).
Each dot on the left side(Power Regen) represent 6kw of energy (4 dots in total).
Image

YES Nissan also change the logo front and back of rebranded leaf in china.
Image

Image
Which I changed back to the original outlook.

Also Chinese version of leaf have spare tire and rear fog light:
Image

Maybe I'll create a dedicated thread for those who interested in Chinese leaf owner.

And yes there are thousand of us and we are having fun:
Image

Xriva18707
Posts: 3
Joined: Wed Dec 02, 2015 7:04 am
Delivery Date: 18 Dec 2015
Location: Northeastern PA USA

Re: Regenerative braking - why have the option to NOT have this?

Wed Aug 03, 2016 4:04 am

I love the regen brake but am annoyed that it does not work when the battery is 100% charged.
But the makes sense, because if the battery is charged there us no room for the regen.

My complaint is that I cannot program the car to stop charging at a certain percentage or battery level.
(2016 SL)

So our car charges to 100%. We live on a mountain and drive down hill for the first 5 miles. But we get no regen because the batt is at 100%. It sucks that we have wear down our brake pads rather than use regen.

I hope Nissan fixes the software so a stop charge % can be set by the user.
Xriva

jjeff
Posts: 1387
Joined: Wed Jan 13, 2016 9:10 am
Delivery Date: 13 Jul 2014
Leaf Number: 422121
Location: MSP MN

Re: Regenerative braking - why have the option to NOT have this?

Wed Aug 03, 2016 6:05 am

Xriva18707 wrote:I love the regen brake but am annoyed that it does not work when the battery is 100% charged.
But the makes sense, because if the battery is charged there us no room for the regen.

My complaint is that I cannot program the car to stop charging at a certain percentage or battery level.
(2016 SL)

So our car charges to 100%. We live on a mountain and drive down hill for the first 5 miles. But we get no regen because the batt is at 100%. It sucks that we have wear down our brake pads rather than use regen.

I hope Nissan fixes the software so a stop charge % can be set by the user.

Doesn't your '16 allow 80% when using the charging timer? My '13 has 80% as a menu option, if set for 80% it only charges to 80% unless one changes the menu option. My '12 lacks the 80% menu option but does allow 80% if charging using the timer. I've setup a timer on my '12 where if I plug it in, it starts charging immediately but only goes to 80%. If I push the timer override button I can get a 100% charge. Does your '16 not even have the 80% with the timer?
I agree, no regen at a high SOC isn't very nice, I love my regen. On my '13 I start gaining back regen very quickly, like one bar available at 98%, two at 96% and by low 90s full regen is available to me. Now my '12 is totally different, I don't get regen until the low 80s SOC and has to be darn near 50% before I get full regen, really bothers me and probably my biggest complaint about the '12. Even with full bars I find the regen(engine breaking) far less on the '12 than '13(I always use ECO and being a S model ECO also includes B mode) not sure why but I know it's the case. On the '13 with full bars I hardly have to use the breaks when exiting a freeway with a long ramp, this is not the case with the '12 where I always have to use at least some friction breaks to stop. I knew right ways when I purchased the '12 used as the wheels were covered in break dust whereas my '13 generally has no break dust on the wheels.

Note even if your '16 lacks the 80% feature you should still be able to simulate it by using the departure time timer. If you plan on leaving for work at 8am set the timer for say 6am and plug your car in the night before. Because your leaving early the car won't be fully charged. Play with the end time and eventually you should be able to figure out a time to set it to so you'll get your desired SOC when you leave. Note for setting the time it matters what the amperage of your EVSE is as well as the current SOC when you plug it in. Not nearly as easy as if they had the 80% option but better than nothing :)
2012 SL purchased used 2/'16
2013 S w/QC purchased new
Juicebox Premium 60a L1/L2 EVSE, Ebusbar 16a L1/L2 EVSE
'12 EVSEupgrade'd 20a L1/L2 EVSE, '13 EVSEupgrade'd adjustable 6-20a L2, 6-13a L1 EVSE
Zencar 13, 20, 30a L1/L2 portable EVSE
GE Durastation 30a

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