2013 B Mode

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BlackLeaf13

Member
Joined
Mar 5, 2013
Messages
15
Location
West Covina, CA
The manual wasn't clear on how to engage B Mode. I was in D Mode and shifted again, left and down. It engaged B Mode. Is it bad for the motor to driving in B Mode all the time?
 
All it does is change regeneration. The motor could not care less.

BlackLeaf13 said:
The manual wasn't clear on how to engage B Mode. I was in D Mode and shifted again, left and down. It engaged B Mode. Is it bad for the motor to driving in B Mode all the time?
 
BlackLeaf13 said:
The manual wasn't clear on how to engage B Mode. I was in D Mode and shifted again, left and down. It engaged B Mode. Is it bad for the motor to driving in B Mode all the time?

not bad but guessing its not going to be a pleasant driving experience
 
I leave it in B ECO all the time and only use the extra regen in place of the brake pedal after coasting in N to the lights or stop sign.
 
LEAFfan said:
DaveinOlyWA said:
Do u always get the max available regen that way when your foot is off accelerator?

It pegs the meter and bubbles at 38mph and drops off below that speed.


so has to be faster than 38 mph? oh well, that kinda sucks since i can do that manually very easily. my issue is not being able to fill those last bubbles at a lower speed where i believe i could really add to my range and save on my brakes (shooting for 200,000 miles instead of a measly 100,000 miles! :D )

was hoping B mode was more like it is on the Prius
 
DaveinOlyWA said:
so has to be faster than 38 mph? oh well, that kinda sucks since i can do that manually very easily. my issue is not being able to fill those last bubbles at a lower speed where i believe i could really add to my range and save on my brakes (shooting for 200,000 miles instead of a measly 100,000 miles! :D )
was hoping B mode was more like it is on the Prius
I'm no expert on either electric motors or the inner guts of the Prius, but I thought the planetary gear in the Prius allowed a second motor/generator to spin much faster than the primary motor/generator when the engine was stopped. My assumption (perhaps incorrect) is that electric motors can't generate as much energy when they are turning slowly. The LEAF has only one motor and its speed, like the speed of the primary motor in the Prius, is always directly synchronized with the speed of the wheels.

Ray
 
planet4ever said:
My assumption (perhaps incorrect) is that electric motors can't generate as much energy when they are turning slowly. The LEAF has only one motor and its speed, like the speed of the primary motor in the Prius, is always directly synchronized with the speed of the wheels.
If by energy you mean power (kW), then you are correct. The LEAF's motor has a fairly flat torque curve from 0 mph to around 30 mph. Power climbs from 0 kW to around 80 kW through those speeds. From 30 mph+, power remains at 80 kW, but torque (and rate of acceleration) falls off.

Power = Torque * RPM
 
DaveinOlyWA said:
LEAFfan said:
DaveinOlyWA said:
Do u always get the max available regen that way when your foot is off accelerator?

It pegs the meter and bubbles at 38mph and drops off below that speed.


so has to be faster than 38 mph? oh well, that kinda sucks since i can do that manually very easily. my issue is not being able to fill those last bubbles at a lower speed where i believe i could really add to my range and save on my brakes (shooting for 200,000 miles instead of a measly 100,000 miles! :D )

was hoping B mode was more like it is on the Prius

Even at less than 38mph, it still gives you really good braking and 3 regen bubbles. I've been using the friction brakes even much less now. At 38 or higher, it's 2 bubbles more regen than '11-'12.
 
How does the leaf handle mountain driving? Either a newer one with B-mode or an older one or 2013 base S model with only Eco? I mean is there something in there like a transmission or something that allows for 'engine braking' or would one really just have to ride the brakes going downhill? That would concern me a bit. Anyone experience this? Fortunately I live in a flat area of the country, but if in the future we finally get our highways electrified with fast chargers and one wanted to take a trip.....
 
hyperlexis said:
How does the leaf handle mountain driving? Either a newer one with B-mode or an older one or 2013 base S model with only Eco?
My experience is that regen braking in ECO is similar to 3rd gear in a 4-speed A/T. B-mode is similar to 2nd gear. No problem taking mountain roads at all in that regard.
 
hyperlexis said:
How does the leaf handle mountain driving? Either a newer one with B-mode or an older one or 2013 base S model with only Eco? I mean is there something in there like a transmission or something that allows for 'engine braking' or would one really just have to ride the brakes going downhill? That would concern me a bit. Anyone experience this? Fortunately I live in a flat area of the country, but if in the future we finally get our highways electrified with fast chargers and one wanted to take a trip.....
The 2011/2012 LEAF is ok on mountain descents but it needed a bit more regen to avoid use of the brake pedal on steep hills. The 2013 with B mode should have improved on that considerably, based on LEAFfan's numbers.

I find that second gear is ideal for safe descents in my manual transmission ICE cars. The LEAF in Eco feels like being in third gear: not enough "engine braking" to keep the car at a safe speed. I am envious of those with the 2013 B mode.


[For the record: my personal definition of "steep" is a hill that requires 18kW or more to maintain a constant velocity of 25 mph going uphill (try it sometime). Such hills are too steep for descending at a safe speed (25-30 mph) in a 2012 model LEAF with just regen braking in Eco.]
 
hyperlexis said:
I mean is there something in there like a transmission or something that allows for 'engine braking' or would one really just have to ride the brakes going downhill?
Nope, no transmission, and none needed. The equivalent of engine braking comes from the brains in the car converting the motor to a generator. And it is all done electronically without shifting any gears. It takes a while for people to fully grasp the simplicity of the mechanical part of the setup. There are some reduction gears between the motor and the wheels, but no clutch and no gear shifting, ever. If the wheels are moving, the motor is spinning, even if you are in "neutral". If the wheels are moving backwards, the motor is spinning backwards. If you are stopped, the motor is stopped. Period.

All the fancy stuff is done by the inverter that controls the motor. It tells the motor which way to spin and how fast, and how much torque to apply to the wheels, or how much "regen" power to pull out of them.

Ray
 
So...I've been driving around with B Mode for a few days. The car really slows down when you lift your foot off the accelator. You have to feather the pedal for a smooth transition. The regen seems to be twice as much as regular D mode. I used the brakes less. It was kinda dangerous when cars were following me close. They couldn't tell I was slowing down that quickly without my brakes. I still have to get use to driving in B mode.
 
newownermnl
BlackLeaf13 said:
So...I've been driving around with B Mode for a few days. The car really slows down when you lift your foot off the accelator. You have to feather the pedal for a smooth transition. The regen seems to be twice as much as regular D mode. I used the brakes less. It was kinda dangerous when cars were following me close. They couldn't tell I was slowing down that quickly without my brakes. I still have to get use to driving in B mode.
I had the same experience when I was transitioning from the LEAF to the ActiveE. I prefer strong regen now, and heard from many others that feel the same way once they get used to it. I think Nissan should considering turning the brake lights on when deceleration reaches a certain level, no matter how it was achieved (brakes or regen). Have fun with your new 2013.
 
LauraA said:
I have a new 2013 Leaf (my second Leaf) and I don't really understand B Mode - even after reading these comments. I live in very flat coastal GA. Is it only really useful with hills? Thanks, LauraA
For the most part yes, B mode is most useful descending hills. However, you could use it to slow quickly for an upcoming stop instead of using the brake pedal, assuming you teach yourself when to shift in time to make the stop. That's the short answer. The longer answer:

B mode can also be used for single pedal driving: accelerating and slowing just using the "A" pedal and using the brake pedal only to hold the car still at a stop. With practice this can be the most efficient way to drive. But to do so one has to get over the idea, which some drivers have, that the A pedal is either "on" or "off": stomp it to go, back all the way off to stop. Instead one has to learn to "feather" the A pedal to adjust speed gently, as needed. Also, be aware that in most situations it is more efficient to coast than to use regen braking. The can be done by shifting to neutral or by using the Eco mode and holding the A pedal at zero power, as shown on the energy screen (if you have it on your 2013 model, I believe that the S model might not have it).

All of this is more trouble than it is worth for some people but it gets fairly easy with practice for those concerned with driving efficiently. It helps if you view it as a game: "how efficiently can I make this trip?" While driving efficiently isn't necessary for short trips it is helpful to know how to do it when trying to stretch the range of a LEAF on longer trips.

FWIW, I am envious of the B mode on your 2013 LEAF. I wish I had it!
 
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