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Discussion Starter #1
Does anyone have a feel for the split between how much regen vs friction braking is happening at certain brake pedal pressures (on a 2017)? I ask because after using the paddle on the steering wheel quite a lot, I've basically given up on the paddle as being too aggressive and now I just use the brakes.

Watching the amount of regen being done as I press the brake pedal (in negative kWH), I seem to be able to get about as much regen as using the paddle just by modulating the brake pedal: without the aggression of the paddle and braking harder than I need to. But I wonder, if I press the brake pedal and see -10 kWH, press it a little more and see -15 kWH, and I keep going, is there a known point at which the brake pads kick in and it's not all regen braking?

Or... maybe when you use the brakes, it's never all regen braking even if you brake lightly? Does it only use regen up to a certain amount of brake pressure, or does it split them and always use at least some friction braking from the pads... mixed in with regen?

Mike
 

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$20 gets you an IR temp reader from.. you know.

Do your own testing and tell us. But be safe stopping on the side of the road and hoping out to point that thing at the discs.

I suspect you'll have to do some aggressive braking before seeing heat at the discs.

These cars are amazing.!!
 

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Drive with the gear selector in L, don't worry, it isn't like L on an automatic. It tells the car to use a light regen when you lift the throttle, increasing the more you lift. You can still drive 100 mph (car max speed) in L, as it is not selecting a gear ratio. It isn't quite 1 pedal driving, but gets close, and makes controlling regen much easier as it will never apply friction brakes (still have to step on the brake pedal for that).

I think with brake it starts out as only regen, and as you press down it will blend in friction only if brake torque demands require more than provided by the regen, but I haven't verified this. I think there is a point once you push past it will engage friction brakes no matter what.
 

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I recall reading on these forums that the "MyVolt" android app and an OBD2 reader can provide an audible alert when the braking transitions from regen to friction.
 

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Seems to me that a regenerative braking system is an effective alternative to a friction braking system for an electric car. Recharging the battery is just an additional bonus feature. Braking decisions should be made in response to traffic conditions, not to a desire to maximize the amount of regen put back into the battery. D, L, and the paddle each provide the Volt with a fixed rate of regen braking, and if "coasting" in these modes produces an insufficient decrease in the car’s speed, the brake pedal can be used to provide braking over the entire regen rate of slowing, with friction braking blended in when regen braking is insufficient.

If regenerative braking can manage the "braking" needs of the vehicle under most normal operating conditions (except, perhaps, to bring it to a complete stop), the friction braking system would be programmed to assist with or take over the braking of the vehicle only when the regenerative braking system cannot produce a sufficient decrease in the car’s speed, or when four-wheel braking is needed, or when the car is in Neutral and there is no connection between the motor and the wheels and thus no regen.
 

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Personally I don't use L or the paddles I find I can get max regen from the brake pedal and do it more smoothly. Often when trying to use L or the paddle I would make my wife car sick.
 

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Discussion Starter #8
Personally I don't use L or the paddles I find I can get max regen from the brake pedal and do it more smoothly. Often when trying to use L or the paddle I would make my wife car sick.
That's why I posted this thread. Using the brakes normally, you have what appears to be a variable version of the paddle that is on the back of the steering wheel. So why not use the brakes: the paddle is useless because it gives you one level and it's too much braking unless you are one of those fools who loves to "race" to red lights and brake last second.

Mike
 

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The Accel/Brake graphic on the instrument display shows you when friction brakes engage. When the ball dips down and turns yellow you're in friction braking. When the ball dips down but it is green, regen. Easy.
 

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That's why I posted this thread. Using the brakes normally, you have what appears to be a variable version of the paddle that is on the back of the steering wheel. So why not use the brakes: the paddle is useless because it gives you one level and it's too much braking unless you are one of those fools who loves to "race" to red lights and brake last second.

Mike
For ordinary stops in an ordinary car, I find that I usually slow the car gradually, then press the brake pedal harder to get a faster rate of deceleration towards the end of the slowdown (followed by slightly lifting up on the brake pedal at the very end to avoid the "jerk" of rapid deceleration when the car comes to a complete stop). In the Volt, I first slow the car gradually with light pressure on the brake pedal, then use the paddle for the second phase (rapid deceleration) while still keeping my foot on the pedal. That way I still have fine control over the deceleration rate (avoiding carsick wife syndrome) yet I know that the rapid deceleration is mostly due to regen and not friction because it's mostly due to use of the paddle.

I have no idea whether this attempt to outsmart the car actually works to increase the ratio of regen to friction, but I don't think it hurts either.
 

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The Accel/Brake graphic on the instrument display shows you when friction brakes engage. When the ball dips down and turns yellow you're in friction braking. When the ball dips down but it is green, regen. Easy.
Aha. Seems useful - to those who are not colorblind.
 

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Discussion Starter #13
The Accel/Brake graphic on the instrument display shows you when friction brakes engage. When the ball dips down and turns yellow you're in friction braking. When the ball dips down but it is green, regen. Easy.
Guess I need to brake harder: I've never seen it turn yellow on braking. :)

Mike
 

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Here's an easy way to FEEL the Regen/Friction split:

As you are braking, shift to neutral. The Regen will stop, but the friction braking will remain. You will be able to feel how much of your deceleration is coming from friction.
 

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Discussion Starter #15
The Accel/Brake graphic on the instrument display shows you when friction brakes engage. When the ball dips down and turns yellow you're in friction braking. When the ball dips down but it is green, regen. Easy.
OK, checked again today: this does not happen on my 2017. There is no yellow. Just green bars when doing regen.

Mike
 

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OK, checked again today: this does not happen on my 2017. There is no yellow. Just green bars when doing regen.
Regen can provide up to -60kW of braking in the Volt. (Bolt EV maxes out at -70kW.) That is quite a bit. So the friction brakes are barely used in normal driving. Mainly just as you pull up to a stop, when you are going too slow for any significant regen.
 

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Discussion Starter #17 (Edited)
The last two charges I've been using only the brake pedal because it agrees more with the way I drive: see a red light way down the road, coast and don't use any brakes if possible. If you need the brakes, plan ahead and use them as little as possible (brake slowly when possible, not hard - like the paddle does). Working great and I don't really see any benefit to that paddle.

Edit: nor do I see any benefit to the "L" mode over "D". I'll modulate the amount of regen with the brake pedal.

Mike
 

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Discussion Starter #19
Have you at least tried driving in L? It is a lot easier to modulate the gas pedal since you don't have to move your foot.
Yeah, briefly. Just felt a little "alien" to me driving that way. Maybe I could get used to it. My golf cart does that and I'm fine with it. :)

Mike
 

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There's a learning curve. I used to coast forever in my Buick.

Coasting is still my main energy saver.

I would ride the brakes then apply more and more, still do that some but there's a pretty heavy rate of deceleration that doesn't use brakes and to use that you have to get pretty close to the stop sign. I was stopping 30 feet before the stop sign so takes some getting used to.

Depends on how much thinking you like to do about this stuff. I'm retired so it's like a hobby.

You can just drive it.

But I have all sorts of routines developed to get all I can out of it.

Depends on the trip I'm taking. 90% is routine trips so I get a lot of chances for fine tuning my driving.
 
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