Any way to enable full regenerative braking/disable creep?

[groman]

Hello All,

I'm currently researching the Spark EV (just came home from a test drive), and it seems mostly right except for the bizarre slushbox emulation mode.
The guy at the dealership told me it's impossible to disable, but I'm wondering if there is a hidden setting somewhere or an aftermarket hack.
Specifically I'm interested in the following:

1) Disabling creep when you let go of the brake pedal. It's an electric car, there is absolutely no reason for it to creep.

2) Fully engaging 100% of regen. braking when the accelerator is released without touching the brake pedal. The brake pedal should apply the pads only when necessary.

Is it possible? If not currently, anybody close to an ECU hack?

 

[Nashco]

Hello All,

I'm currently researching the Spark EV (just came home from a test drive), and it seems mostly right except for the bizarre slushbox emulation mode.
The guy at the dealership told me it's impossible to disable, but I'm wondering if there is a hidden setting somewhere or an aftermarket hack.
Specifically I'm interested in the following:

1) Disabling creep when you let go of the brake pedal. It's an electric car, there is absolutely no reason for it to creep.

2) Fully engaging 100% of regen. braking when the accelerator is released without touching the brake pedal. The brake pedal should apply the pads only when necessary.

Is it possible? If not currently, anybody close to an ECU hack?

1) Shift to neutral. No creep applied! I also don't care for creep torque, so I often shift to neutral at a stop light or similar, which has the side benefit of killing the noise maker (which I find REALLY annoying when the radio is off and I just want silence).

2) Technically, the Spark EV has what's referred to as "blended" braking (click here for more info). When you press the brake pedal, the vehicle calculates what the driver's intended braking torque is based on the pedal application, then applies the appropriate amount of regenerative braking. If the force you "intend" is greater than the available regenerative torque, the maximum regen is applied and the friction brakes are applied to make up for the difference between intended braking and available regen.

In short, what this means is that when you press the brake pedal, *very* little energy is wasted to friction IF the powertrain has enough regeneration capability to prevent it. Your desire of "brake pedal should apply the pads only when necessary" is exactly how it comes from the factory, which is necessary for the incredible efficiency of this car. You'll notice when you apply the brake pedal that the "power gauge" will have a noticeable increase in power going back into the battery compared to normal accelerator-pedal-up power levels. You can get as much as 60 kW of regen power while applying the brake pedal, which highlights that the powertrain is doing the best it can to prevent wasting energy to heat!

I know of methods to make "creep" go away without shifting to neutral, but none that give full functionality otherwise (ie. they cause "reduced propulsion" mode and poor brake blending as well).

Bryce

 

[SteveC5088]

Yep, I shift to N at stop lights, too. I really like the creep when parking and backing. It would be tough to learn to touch the pedal just lightly enough to enable creeping speed. In fact, a slight mistake could cause the car to rocket forward or back and hit something in those tight parking situations.

I would agree with Bryce that, with the shifter in L, very little energy is lost to brake pad friction. I practice using L, and lightly stepping on the brake pedal. It really slows the car as if I were braking heavily in an ICE-driven car.

By the way, in the Spark, when you are in L, and let up on the accelerator all the way, the brake lights turn on, even without your touching the brake pedal.

 

[groman]

I don't want any brake blending. I just don't want to use the brake pedal at all in normal driving. It will be more efficient if "No Pedals Pressed" meant full regenerative braking applied, like on the i3, Tesla, ActiveE etc.

As far as creep goes, I'm not used to it because I currently drive a manual, and it's very annoying.

So, no mods that enable this?

 

[xylhim]

I don't want any brake blending. I just don't want to use the brake pedal at all in normal driving. It will be more efficient if "No Pedals Pressed" meant full regenerative braking applied, like on the i3, Tesla, ActiveE etc.

As far as creep goes, I'm not used to it because I currently drive a manual, and it's very annoying.

So, no mods that enable this?

So the L mode on the Spark will allow you to drive without using the brake at all, and slows the car using 100% regen. It's only when you press the brake too hard that it switches to disk. Every electric car, even the Tesla and i3 have friction brakes to slow the car down in the event of needing to come to a sudden stop. Now, that doesn't mean that driving in L mode is the most efficient. Remember, you can't recoup all the energy that you spent accelerating to a certain speed, waste heat is always generated in any energy conversion system, even in regenerative braking. So it's best to try to maintain a constant speed by using your cruize control, then if you see that you may need to stop, disengage the cruise and switch it to D mode to slowly decrease speed, this way if you have to speed back up, you don't have to use as much energy to go back to your original velocity.

 

[cwerdna]

1) Disabling creep when you let go of the brake pedal. It's an electric car, there is absolutely no reason for it to creep.

Don't know of any. Some ask for it on the Leaf as well.

There are reasons for creep. See http://www.mynissanleaf.com/viewtopic.php?p=348698#p348698 and http://edocket.access.gpo.gov/2003/03-12051.htm. To steal from http://techno-fandom.org/~hobbit/cars/prius-linkfarm.html "NHTSA/DOT starter interlock and transmission safety standards NPRM for hybrids, that explains the whole rationale about "creep" force and directional cueing for a driver. "

 

[Nashco]

I don't want any brake blending. I just don't want to use the brake pedal at all in normal driving. It will be more efficient if "No Pedals Pressed" meant full regenerative braking applied, like on the i3, Tesla, ActiveE etc.

What makes you believe that when you press no pedals in those cars that you get "full" regenerative braking?

There aren't any modifications that will give maximum possible regen torque without pressing the brake pedal. There's little interest in aftermarket support for this car, so something like that would have to come from an enthusiast. If you're handy with computers, you can join in with us on trying to tap into the CAN signals to figure out how to do this...

http://www.mychevysparkev.com/forum/viewtopic.php?p=9256

Bryce