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A couple minor factual inaccuracies. > Where the electric motor really delivers is in torque - 210 ft-lbs of it. And not only that, electric motors deliver the

A couple minor factual inaccuracies. > Where the electric motor really delivers is in torque - 210 ft-lbs of it. And not only that, electric motors deliver the same torque over most of their speed range, starting at 0rpm. Uh, no. Electric motors don't work that way. They produce their max torque at 0 rpm and it decreases from there. This is also the point where it generates the most heat and uses the most current. >You step on the accelerator, and the car instantly goes. It's a combination of the torque in the electric motor and the CVT (continuously variable transmission). No documentation I have found states it has a CVT. Most sources I've found say it has a single speed with a reduction of 7.94:1. -Edit- But the statement about the torque is very much true. It is a significant benefit of electrics over ICE. Aside these, I'm looking forward to hearing how this car performs in the winter. I want to know if I can recommend this car to my mother back in Michigan.

koblenski 13y ago
> They produce their max torque at 0 rpm and it decreases from there. That's true in an unregulated motor, but Nissan electronically regulates the motor so the torque isn't ridiculous at 0rpm. The torque curve ends up being flat over most of the range, and it seems to start falling off around 50mph. I haven't seen a plot, so that's just my impression. I can see how the wording is incorrect, so I modified it to refer specifically to the Leaf's motor. > No documentation I have found states it has a CVT. You're right. Fixed.
- schreiaj 13y ago
  Thanks. Do you have any information about this regulation? I'd like to learn more about how it works.
  - koblenski 13y ago
    I'm having difficulty finding articles specific to the Leaf's motor, but there's a nice explanation for EV motors in general here: http://www.diyelectriccar.com/forums/showthread.php/why-do-electric-motors-have-constant-55282.html http://www.diyelectriccar.com/forums/showthread.php/why-do-e... Basically, the motor controller limits the current below its maximum so the amount of torque output will remain constant until it drops below the current limit. There's an explanation of different current limiting methods here: http://homepage.cs.uiowa.edu/~jones/step/current.html http://homepage.cs.uiowa.edu/~jones/step/current.html The Leaf's controller likely uses an active current limiting method, and there's a lot of advances in this technology right now. That's where a lot of the motor efficiency improvements are coming from. Surprisingly, I can't find much good info on Wikipedia, but I'm probably not using the right search terms.

koblenski 13y ago

> They produce their max torque at 0 rpm and it decreases from there. That's true in an unregulated motor, but Nissan electronically regulates the motor so the torque isn't ridiculous at 0rpm. The torque curve ends up being flat over most of the range, and it seems to start falling off around 50mph. I haven't seen a plot, so that's just my impression. I can see how the wording is incorrect, so I modified it to refer specifically to the Leaf's motor. > No documentation I have found states it has a CVT. You're right. Fixed.

schreiaj 13y ago
Thanks. Do you have any information about this regulation? I'd like to learn more about how it works.
- koblenski 13y ago
  I'm having difficulty finding articles specific to the Leaf's motor, but there's a nice explanation for EV motors in general here: http://www.diyelectriccar.com/forums/showthread.php/why-do-electric-motors-have-constant-55282.html http://www.diyelectriccar.com/forums/showthread.php/why-do-e... Basically, the motor controller limits the current below its maximum so the amount of torque output will remain constant until it drops below the current limit. There's an explanation of different current limiting methods here: http://homepage.cs.uiowa.edu/~jones/step/current.html http://homepage.cs.uiowa.edu/~jones/step/current.html The Leaf's controller likely uses an active current limiting method, and there's a lot of advances in this technology right now. That's where a lot of the motor efficiency improvements are coming from. Surprisingly, I can't find much good info on Wikipedia, but I'm probably not using the right search terms.