j5hale3
Posts: 8
Joined: Thu Jul 11, 2013 11:56 am
Delivery Date: 08 Jul 2013
Leaf Number: 411604
Location: Central NJ USA

Re: Have B Mode as Deflaut Drive Mode

Fri Sep 19, 2014 10:04 am

I've just recently come to a conclusion regarding most of these "improvement threads". More features should be user adjustable. My first year of use was mostly in B mode and I would have supported this suggestion. Now, I use a both modes as needed. One "advantage" of having the D mode as the first selection allows a smoother transition from the Neutral coasting to the powered driving mode. So now it is not much of a difference to me which mode is primary.

One thing I would love to fix is the backwards shifter. I know the most vocal members of our community think the current implementation is more correct but the shifter motion is the opposite of an automatic transmission when going from the Park position to the Reverse position. In my driveway, parking lot stall, and most of the time from parallel parking I need to use reverse first and in an automatic transmission, you move the selector down or backwards to get into Reverse, whereas in the leaf you move it forward. If that is not the opposite, I don't know what is. The big difference is that the shifter then moves back to a middle position in the leaf but not in regular automatics.

I also wish the cruise control was a "sticky" button. I want the availability of CC to be ready at any time I select the set function and not have to remember to turn it on each time I start the car. Once again this should be user "settable" and in a similar manner, the last nav screen I use should be the one that comes on the next time I start the car.
2013 Leaf SL (Premium Package) in Slate Gray

brant
Posts: 2
Joined: Thu Oct 02, 2014 9:49 am
Delivery Date: 20 Sep 2014
Leaf Number: 2013

Re: Have B Mode as Deflaut Drive Mode

Thu Oct 02, 2014 10:03 am

I've had my leaf for about a week. I like driving in B mode better than "D" mode.

Question: when I take my foot off the accelerator in "B" mode and the regenerative braking kicks in, does this cause the brake lights (visible to the car behind me) to come on?

nerys
Posts: 699
Joined: Tue Sep 09, 2014 10:11 pm
Delivery Date: 09 Sep 2014
Leaf Number: 020441

Re: Have B Mode as Deflaut Drive Mode

Thu Oct 02, 2014 10:53 am

no if you need them to just touch the brake pedal a little. you won't activate the brakes but you will activate the brake lights.
2012 SV 4802miles. 1month 2400 miles. 9 weeks 5000 miles. 6 months 13,300 miles. 4/18 15,000 miles.

minispeed
Posts: 681
Joined: Sun Jul 06, 2014 4:52 am
Delivery Date: 15 Jul 2014
Location: Ancaster, ON

Re: Have B Mode as Deflaut Drive Mode

Thu Oct 02, 2014 12:50 pm

Wow this comes up a lot.....

B mode, what it's for, going down hills. Regen, it will not ever ever ever add range. Energy comes out of the battery, over comes losses friction heat etc... gives x% to the car as kinetic energy. At cruise you use just enough energy to overcome all those losses. You then want to convert that kinetic energy back into the battery it will have to over come losses and give y% of x% back to the battery. This will never add range. If you want to go further coast to your stop. Period. Done. You cannot beat that method. If for example you are going to travel from 0mph at point A to point B where you are steady 60mph then at point C you start to slow to again be at 0mph at point D.

Regen:
Acceleration energy A-B. Cruise energy B-C, since you are amazing you capture the highest possible amount from C-D using the smallest amount of friction brake possible that the car will physically allow.

Coast:
Acceleration energy A-B is the same as above. Cruise energy B-C is less since you will have to start C sooner. Since you are amazing you start C at the perfect time so that with no regen and no friction brakes you arrive at D at 0mph in the exact same spot as above.

The net energy remaining in the battery from the coast scenario will always be higher because the savings you get from moving point C leaves more in the battery than regen C-D can ever put back in.

In B mode it is more difficult to coast, and more costly if you accidently use too much regen while trying to get a coast. In Eco mode it is easier to coast and you get more regen with a full lift off the pedal but no brakes. I'd estimate 75% of B mode. In Eco mode it is also very easy to modulate the brake pedal to get the same regen as B mode without engaging any significant amount of friction brakes (or even none). If you don't want to learn to feather the brake then use B but it's safer to feather the brake because your lights go on.

Since B mode is for going down hills it is designed to capture gravitational potential energy that if converted to kinetic energy would cause you to speed. Since we want to be good boys and girls (and also not have too much drag) we don't want to get too fast and end up using friction brakes to burn off that energy quickly when we notice we are in ticket zone.

What you can do is find out how to use regen and coasting to your advantage so that you ballance moving with traffic, getting to your destination in an acceptable time and using the least energy possible. In the real world with traffic lights as an example you have 3 things that happen most often.
1. It goes yellow and you're close to it, you hit the brakes hard. In B, Eco or D you'll put pretty much the exact same energy back into the battery.
2. It's red when you approach and you're far away, but close enough that it probably won't turn green if you keep cruising at your speed. To use B properly you have to maintain cruise and keep using energy then when closer you start to use regen. You will get to the lights quicker, if it's still red you now have 0 kinetic energy. If you coast as soon as you see the light you are now in a situation where you are using no energy, it will take you longer to get to the light so there is a greater chance it will go green before you get there and you then get to accelerate from said speed instead of 0 and you will use less energy to get back up to cruise. If you do end of stopping at the light same as above with A-B-C-D what you saved by coasting early will be more than you put back into the battery.
3. It's green the whole time, same energy in all modes.
Last edited by minispeed on Thu Oct 02, 2014 4:05 pm, edited 1 time in total.
2015 White SV, after one month 292 GIDS
Best 1 charge drive, 229km (143miles)

nerys
Posts: 699
Joined: Tue Sep 09, 2014 10:11 pm
Delivery Date: 09 Sep 2014
Leaf Number: 020441

Re: Have B Mode as Deflaut Drive Mode

Thu Oct 02, 2014 2:45 pm

You are incorrect.

On paper your right. 100% coast is almost always better

Alas the car does not operate on paper it operates in reality

In reality you can not easily and or legally coast to 100%

You must retain velocity beyond the ideal coast point it almost all decels otherwise you will piss of other drivers and or the police.

So no matter what your going to burn up attained energy. Might as well recover a little of it with regen.

While it wont increase your overall max range it will increase your effective range over what you would have gotten without it.
2012 SV 4802miles. 1month 2400 miles. 9 weeks 5000 miles. 6 months 13,300 miles. 4/18 15,000 miles.

minispeed
Posts: 681
Joined: Sun Jul 06, 2014 4:52 am
Delivery Date: 15 Jul 2014
Location: Ancaster, ON

Re: Have B Mode as Deflaut Drive Mode

Thu Oct 02, 2014 4:02 pm

nerys wrote:You are incorrect.

On paper your right. 100% coast is almost always better

Alas the car does not operate on paper it operates in reality

In reality you can not easily and or legally coast to 100%

You must retain velocity beyond the ideal coast point it almost all decels otherwise you will piss of other drivers and or the police.

So no matter what your going to burn up attained energy. Might as well recover a little of it with regen.

While it wont increase your overall max range it will increase your effective range over what you would have gotten without it.

In the real world you can use a lot of coasting and not do anything dangerous. You may piss off people coasting towards a red light but you will not piss off the police. I know every state is different but I doubt a single one has a charge for slowing down too early for a red light. Think for a second how the real world applies to the real world situations I gave. Now maybe it's my fault for not clarrifying that I was only talking about lights you see that you are also close enough to that you will have to stop or slow down for. If you can see a mile and it's red and a 25mph limit I'm not saying coasting is the best at that time. So if you coast as soon as you see a red light that you will probably have to stop for but you are far enough away that you don't need to brake yet you will not get down to a speed that is dangerous slow for that road by coasting. You will save energy by not using it to maintain speed and this will also allow you to retain kinetic energy in case the light turns green before you stop. If you count on regen in that same time you will have travelled further while using energy to maintain speed then scrubbed off more speed and then have to call on more power to get back up to speed.

If B mode gave more range it would show up on the EPA tests and then logically it would be the default.
2015 White SV, after one month 292 GIDS
Best 1 charge drive, 229km (143miles)

nerys
Posts: 699
Joined: Tue Sep 09, 2014 10:11 pm
Delivery Date: 09 Sep 2014
Leaf Number: 020441

Re: Have B Mode as Deflaut Drive Mode

Thu Oct 02, 2014 4:24 pm

Regen does not give more range. NO regen gives more range. That's impossible.

it reduces your range LOSSES from your mistakes in braking (required or not)

an ideal coast is letting off the accelerator at the proper distance so that touching NOTHING including the brakes you roll to a full stop at the stop light on inertia alone.

the moment you NEED to apply the brakes REGEN can help. the only time regen won't help at all is if you can drive without ever needing to touch the rakes while over 5mph

it does not ADD mileage. it REDUCES how much mileage you would have LOST to the brakes.

so lets say your car can go 80 miles. but you use the brakes too much burning up coasting distance so you can only go 70 miles. but instead of braking you use regen and now you can go 73 miles.

you did not GAIN any miles. you still lost 7 miles. but 7 miles lost is better than 10 miles lost.

See what I mean?
2012 SV 4802miles. 1month 2400 miles. 9 weeks 5000 miles. 6 months 13,300 miles. 4/18 15,000 miles.

minispeed
Posts: 681
Joined: Sun Jul 06, 2014 4:52 am
Delivery Date: 15 Jul 2014
Location: Ancaster, ON

Re: Have B Mode as Deflaut Drive Mode

Thu Oct 02, 2014 4:55 pm

nerys wrote:Regen does not give more range. NO regen gives more range. That's impossible.

it reduces your range LOSSES from your mistakes in braking (required or not)

an ideal coast is letting off the accelerator at the proper distance so that touching NOTHING including the brakes you roll to a full stop at the stop light on inertia alone.

the moment you NEED to apply the brakes REGEN can help. the only time regen won't help at all is if you can drive without ever needing to touch the rakes while over 5mph

it does not ADD mileage. it REDUCES how much mileage you would have LOST to the brakes.

so lets say your car can go 80 miles. but you use the brakes too much burning up coasting distance so you can only go 70 miles. but instead of braking you use regen and now you can go 73 miles.

you did not GAIN any miles. you still lost 7 miles. but 7 miles lost is better than 10 miles lost.

See what I mean?

Yes I see exactly what you mean but I think you are missing what I mean. So your car can go 80 miles in that never touch the brakes situation you gave or does 70 miles using only friction brakes. Then if you maximize your use of regen you get 73 miles (3 from recovered energy). What I am saying from my original reply to this post "What you can do is find out how to use regen and coasting to your advantage so that you ballance moving with traffic, getting to your destination in an acceptable time and using the least energy possible." Is that if you use coasting as much as you can then the net range will be more than when you maximized regen. IE you get a range of 75 miles, 3.5 saves from coasting early and 1.5 of it was from recovered energy cause you had to use some regen in the real world.

There will be times in the real world where coasting is not an option, there will be times when it is. If you use it when it is an option instead of regen it is more efficent.

The main points in relation to this post are that B mode does not give access to more regen, you can get the same amount in D or eco, but because it brings it on quicker it will make coasting using the right foot harder and less efficent. Also if you scrub off too much speed because you are in B mode and you end up not having to stop the loss of having to get back up to speed has a huge impact on range.
2015 White SV, after one month 292 GIDS
Best 1 charge drive, 229km (143miles)

nerys
Posts: 699
Joined: Tue Sep 09, 2014 10:11 pm
Delivery Date: 09 Sep 2014
Leaf Number: 020441

Re: Have B Mode as Deflaut Drive Mode

Thu Oct 02, 2014 4:59 pm

Correct. Coasting should always net you the most efficiency.

alas we can never perfectly optimize coast and must use the brakes. Regen lets us get some of that back. miles that otherwise would have burned up in the brake pads.
2012 SV 4802miles. 1month 2400 miles. 9 weeks 5000 miles. 6 months 13,300 miles. 4/18 15,000 miles.

lorenfb
Posts: 2249
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: Have B Mode as Deflaut Drive Mode

Fri Oct 03, 2014 12:40 am

"Regen lets us get some of that back. miles that otherwise would have burned up in the brake pads."

Oh, so it does provide some energy recovery and additional energy means more miles, right? If not, then
the engineers at Tesla, BWM, and Nissan need to re-take their Physics 101 classes from these recent
thread posts and re-think having regen modes. How could such a basic theory been so over looked,
that Leaf forum members could understand physics better than those automotive engineers?

In these posters reality, there are no other vehicles on the road, no stop signs, no speed limits, and no
safety issues when driving a car.
#1 Leaf SL MY 9/13: 74K miles, 48 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 4.5K miles, 115 Ahrs, 5.5 miles/kWh (average), Hx=98, SOH=99, DOD > 20%, temp < 105F

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