5 ms·

I believe that if people drove exactly the samemas before, they wouldn't get full benefit of regen, but I don't believe people will drive the same as before. I

by JeffL 6y ago

I believe that if people drove exactly the samemas before, they wouldn't get full benefit of regen, but I don't believe people will drive the same as before. I know I don't. Driving without ever using the brakes in my Model 3 is smoother and a bit of a fun mini game. One quickly learns not to accelerate quite as much when there's a visible red light ahead and how much the Regen brakes will slow the car down.

andrewmunsell 6y ago
I find my experience to be exactly the same with the couple EVs I've owned. You very quickly adapt to learning exactly when you need to let off the accelerator, and even going from EV-to-EV where the regen curve is different, it only takes a couple tries to adapt to the new vehicle again.
- jdofaz 6y ago
  The e-Pedal in the Nissan Leaf is wonderful, if you lift your foot off of the accelerator completely the car will apply optimal regen until the car stops. Its really freeing not to have to look at the regen gauge at all, I just keep my foot over the brake pedal just in case I need to stop quicker than the regen braking.
  - mrfusion 6y ago
    What if you’re going down a slight decline where you could normally coast and maintain your speed. Do you have to leave your foot on the pedal and waste battery?
    - CarVac 6y ago
      It's not wasting battery if you have your pedal in the position where it's coasting, neither regenerating nor accelerating.
    - JeffL 6y ago
      If you want to coast, you have to apply slight pressure to the accelerator. It doesn't use battery. It's a little weird at first, but you get used to it in a couple days, then it's second nature.
    - jdofaz 6y ago
      Its really intuitive, if you are going a little too fast you just let up the pressure on the pedal. You don't have to think about if it needs to use battery, regen or coast to maintain the speed you want. In that aspect its like using cruise control in other hybrids/ev.
cultofmetatron 6y ago
a supercapacitor could suck up all that sudden power and send it right back out to get the vehicle moving again.
- mrfusion 6y ago
  Say a 0-60 start needs 20KW for 10 seconds. That’s 200,000 joules? How far away are we from a set of capacitors that can store that?
  - londons_explore 6y ago
    0.5 * 1850 kg * ((60 mph)^2) = 665 483.056 joules Supercaps are 28800 Joules per liter, so you'd be needing nearly 700 liters of them to store the energy of the car decelerating from 60 mph once. 700 liters is a lot of volume in a car where you already use a lot of the available volume for batteries - it's more than the trunk and frunk combined on a Model3.
    - m4rtink 6y ago
      That might still be doable for a delivrry van or a bus, even if it is heavier. Natural gas powered already have quite a big "hump" on top for the pressure botzles with gas, I could imagine putting the supercaps there and the regular batteries inside the chasis to keep the center of gravity low.
  - Obi_Juan_Kenobi 6y ago
    0-60 certainly is not the important metric for this application, perhaps aside from rural routes. Most residential delivery, you're maxing out at 30mph.
    - samatman 6y ago
      Correct, and given that the velocity is squared in the energy equation, this is an enormous difference.
  - 6y ago
ogre_codes 6y ago
I don't think commercial drivers are going to be paying attention to regen rates as they are trying to make 300 deliveries on their daily run. For personal vehicles it makes a lot more sense, particularly when you realize using regen braking means less brake and battery wear so it helps lower maintenance. I do similar things with the fuel economy gauge in my car.
- floatrock 6y ago
  Good insight -- the incentives are on maximizing number of deliveries per unit time. I certainly hear (and sometime even see) UPS drivers gunning their giant diesel vans down my street only to hit a stop sign every block. So the interesting question is can operating costs make their way into the incentive structure (theoretically it should be able to with good vehicle telemetry). Whether it's worth it or not to adopt that incentive structure is another question: is the cost of fuel and maintenance greater or less than the marginal revenue from each additional package? Because you're right, currently the incentives are infamous for maximizing number of deliveries. However, the famous UPS-minimize-left-turns routing optimization story suggests operating costs do factor in as well.
  - ogre_codes 6y ago
    > So the interesting question is can operating costs make their way into the incentive structure. It would likely be easier to just increase vehicle efficiency in the form of better braking, lighter vehicles, higher battery density, etc.

by JeffL 6y ago

andrewmunsell 6y ago

I find my experience to be exactly the same with the couple EVs I've owned. You very quickly adapt to learning exactly when you need to let off the accelerator, and even going from EV-to-EV where the regen curve is different, it only takes a couple tries to adapt to the new vehicle again.

jdofaz 6y ago
The e-Pedal in the Nissan Leaf is wonderful, if you lift your foot off of the accelerator completely the car will apply optimal regen until the car stops. Its really freeing not to have to look at the regen gauge at all, I just keep my foot over the brake pedal just in case I need to stop quicker than the regen braking.
- mrfusion 6y ago
  What if you’re going down a slight decline where you could normally coast and maintain your speed. Do you have to leave your foot on the pedal and waste battery?
  - CarVac 6y ago
    It's not wasting battery if you have your pedal in the position where it's coasting, neither regenerating nor accelerating.
  - JeffL 6y ago
    If you want to coast, you have to apply slight pressure to the accelerator. It doesn't use battery. It's a little weird at first, but you get used to it in a couple days, then it's second nature.
  - jdofaz 6y ago
    Its really intuitive, if you are going a little too fast you just let up the pressure on the pedal. You don't have to think about if it needs to use battery, regen or coast to maintain the speed you want. In that aspect its like using cruise control in other hybrids/ev.

cultofmetatron 6y ago

a supercapacitor could suck up all that sudden power and send it right back out to get the vehicle moving again.

mrfusion 6y ago
Say a 0-60 start needs 20KW for 10 seconds. That’s 200,000 joules? How far away are we from a set of capacitors that can store that?
- londons_explore 6y ago
  0.5 * 1850 kg * ((60 mph)^2) = 665 483.056 joules Supercaps are 28800 Joules per liter, so you'd be needing nearly 700 liters of them to store the energy of the car decelerating from 60 mph once. 700 liters is a lot of volume in a car where you already use a lot of the available volume for batteries - it's more than the trunk and frunk combined on a Model3.
  - m4rtink 6y ago
    That might still be doable for a delivrry van or a bus, even if it is heavier. Natural gas powered already have quite a big "hump" on top for the pressure botzles with gas, I could imagine putting the supercaps there and the regular batteries inside the chasis to keep the center of gravity low.
- Obi_Juan_Kenobi 6y ago
  0-60 certainly is not the important metric for this application, perhaps aside from rural routes. Most residential delivery, you're maxing out at 30mph.
  - samatman 6y ago
    Correct, and given that the velocity is squared in the energy equation, this is an enormous difference.
- 6y ago

ogre_codes 6y ago

I don't think commercial drivers are going to be paying attention to regen rates as they are trying to make 300 deliveries on their daily run. For personal vehicles it makes a lot more sense, particularly when you realize using regen braking means less brake and battery wear so it helps lower maintenance. I do similar things with the fuel economy gauge in my car.

floatrock 6y ago
Good insight -- the incentives are on maximizing number of deliveries per unit time. I certainly hear (and sometime even see) UPS drivers gunning their giant diesel vans down my street only to hit a stop sign every block. So the interesting question is can operating costs make their way into the incentive structure (theoretically it should be able to with good vehicle telemetry). Whether it's worth it or not to adopt that incentive structure is another question: is the cost of fuel and maintenance greater or less than the marginal revenue from each additional package? Because you're right, currently the incentives are infamous for maximizing number of deliveries. However, the famous UPS-minimize-left-turns routing optimization story suggests operating costs do factor in as well.
- ogre_codes 6y ago
  > So the interesting question is can operating costs make their way into the incentive structure. It would likely be easier to just increase vehicle efficiency in the form of better braking, lighter vehicles, higher battery density, etc.