How do the brakes/regen work in tandem?

[mattadata]

I usually drive around in B mode. I like the extra regen. I actually wish it were more aggressive so we could drive with nearly one pedal most of the time.

So when do the hydraulic disc brakes kick it? Do they start working as soon as I step on the brake pedal? Or is the first part of the brake pedal regen only, then as I push harder, the disc brakes kick in?

Similar question about ‘creep’…..when you are at a stop let off brake and start moving forward. It feels like the electric motor is trying to push forward and I am holding it back with the disc brakes. That can’t be true. Is it just really sensitive and as I let off the brake the electric motor comes on?

Thanks!

 

[arnis]

Regen is limited to 30kW without brake pedal.
If you push brake pedal slowly and lightly you add a little bit of friction brakes.
If you kick brake pedal a little bit harder/faster Leaf will apply more regen (up to 50kW).
If you add more braking power (more than regen is capable) friction brakes add that.
You can see when Leaf uses friction brakes with ecotree dial. If dots dissappear that means
more and more friction braking is used.

Leaf has constant creep mode. Electric motor is constantly trying to go. You stop it only with
friction brakes. I know that it is a little bit of stupid but what can we do. Nissan is not smart.

Regen is not available at speed slower than walking (down to creep speed).

 

[GerryAZ]

Creep does not waste energy because the controllers turn off power to the motor as long as you press the brake pedal. Power is applied to the motor to create torque and give the feel of creep as soon as you release pressure on the brake pedal. If you set the parking brake and take your foot off the service brake pedal, power will be supplied to the motor to create torque so that would waste a small amount of energy. Allowing the creep function of the motor to hold the car stationary on a slope wastes energy so you need to press the service brake pedal whenever you are stopped unless the car is in neutral or park.

Gerry

 

[LeftieBiker]

Creep does not waste energy because the controllers turn off power to the motor as long as you press the brake pedal. Power is applied to the motor to create torque and give the feel of creep as soon as you release pressure on the brake pedal. If you set the parking brake and take your foot off the service brake pedal, power will be supplied to the motor to create torque so that would waste a small amount of energy. Allowing the creep function of the motor to hold the car stationary on a slope wastes energy so you need to press the service brake pedal whenever you are stopped unless the car is in neutral or park.

Gerry

Yes. This has been the standard operating mode for electric bicycles and motorcycles for years. The brakes and Regen operate together, but not the brakes and motor in Drive mode.

 

[arnis]

Creep does not waste energy because the controllers turn off power to the motor as long as you press the brake pedal. Power is applied to the motor to create torque and give the feel of creep as soon as you release pressure on the brake pedal. If you set the parking brake and take your foot off the service brake pedal, power will be supplied to the motor to create torque so that would waste a small amount of energy. Allowing the creep function of the motor to hold the car stationary on a slope wastes energy so you need to press the service brake pedal whenever you are stopped unless the car is in neutral or park.

Gerry

Unfortunately this is not true. Creep is active even with brake pedal (definitely true for 2014 Leaf).
Motor applies very slight torque. Less than 200W for sure.
I can feel the torque while holding brake pedal. And I can feel when torque disappearing when I shift into N while holding brake pedal.

If you think that this only applies to very light brake pedal push then try again while stopped on a hill nose down. Find minimum
braking force. Release very slowly, brakes start to squeal and then shift into Neutral. Car will stop because creep torque disappears.

 

[GerryAZ]

Creep does not waste energy because the controllers turn off power to the motor as long as you press the brake pedal. Power is applied to the motor to create torque and give the feel of creep as soon as you release pressure on the brake pedal. If you set the parking brake and take your foot off the service brake pedal, power will be supplied to the motor to create torque so that would waste a small amount of energy. Allowing the creep function of the motor to hold the car stationary on a slope wastes energy so you need to press the service brake pedal whenever you are stopped unless the car is in neutral or park.

Gerry

Unfortunately this is not true. Creep is active even with brake pedal (definitely true for 2014 Leaf).
Motor applies very slight torque. Less than 200W for sure.
I can feel the torque while holding brake pedal. And I can feel when torque disappearing when I shift into N while holding brake pedal.

If you think that this only applies to very light brake pedal push then try again while stopped on a hill nose down. Find minimum
braking force. Release very slowly, brakes start to squeal and then shift into Neutral. Car will stop because creep torque disappears.

My 2011 did not and my 2015 does not supply current to the traction motor in Drive, ECO, B-mode (2015 only) or Reverse with foot on service brake pedal. It does take a little pressure on the brake pedal to turn off the current which causes creep and the current is switched back on as soon as you release pressure on the brake pedal.

Gerry

 

[arnis]

How much pressure on brake pedal is necessary?
How did you measure current? Clamps?

 

[GlennD]

My eGolf does not creep. My 2 Leaf's and my B did. I think I really prefer a little creep.

 

[BrockWI]

I am not sure if there is a second sensor on the foot brake, but if I push the brakes lightly, the car will stop moving and Leaf Spy says there is still power being used by the motor, if I press the brake pedal further at some point the motor power does shut off. I also notice this at longer light I now push the pedal way down and then back off a bit, when you fully take your foot off the brake you can feel for a split second there is no creep. If I only lightly press the creep is always there.