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If you had a choice: Acceleration or Distance?

Discussion in 'Model 3' started by Garlan Garner, Jul 1, 2016.

?

Where might you want the focus of a battery enhancement directed?

  1. Acceleration

    37 vote(s)
    13.2%
  2. Distance

    244 vote(s)
    86.8%
  1. Booga

    Booga Member

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    A part of the difference is that not everyone is able to charge as frequently as we might like.

    I'm hoping to have a charging spot installed at my home (a condo, which I own, and am on the board of the HOA for), but if it runs me $4-5k, I might have to pass. In that case, I'll either find another way to charge (maybe at an alternative parking location close enough to work) or even just get used to going somewhere for an hour once or twice a week while my car charges at a chademo or supercharger location. The more common they become, the less of an issue this will be, but until then, there is still some work required on my part.

    For my situation, the difference between 200 miles and, just for discussion's sake, say 300 miles or even 400 miles of range is huge. If the car had a 400 mile range, it would be no discussion - I could charge once a week to 80% or 85% and not worry about range. With 300 miles of range, I'll realistically need to charge twice in order to be able to make the trips I want to. At 200 miles of range, I'm extremely limited, especially in the winter when temperatures are often in the single digits (fahrenheit).

    I'm an early adopter of technologies in general and definitely enjoy my "toys" and so I'll make this work no matter what it takes, but the math of $5,000 to get a charging location is a part of why I'm not entirely sure yet if I can get a full charge at home. If I had that, it would be less of an issue. (Though I still think 300 miles of range for my weather conditions is needed, because of battery degradation over 10 years and because winter weather can be pretty brutal)
     
  2. EaglesPDX

    EaglesPDX Member

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    Tesla disagrees with your view as Teslas biggest reason for success is that it went for the 250 mile range vs. 100 mile range of Leafs and others.

    Skiing in cold weather for me is 125 miles with very frequent issues of traffic jams, snow and ice that crush range. 200 mile range for that trip is inadequate. It's not a "per day" but it is 30 days a year.

    Smaller motors (less acceleration but greater range) and lower weight (greater range) are key to the T3 being a car the family car Tesla want it to be.

    In every study of consumer behavior, the range of the EV's is key to the buying decision.
     
    • Like x 1
  3. JeffK

    JeffK Well-Known Member

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    If the rumors from before the launch are true then we know there might be a sub 4 second 300 mi model.
     
  4. EaglesPDX

    EaglesPDX Member

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    Then Tesla is "deluding us" as smaller motors translate to 8% range gains.

    Because EV motors are so perfect for towing with instant high torque at low speed the drop in the HP leaves huge amount of torque for towing.
     
  5. JeffK

    JeffK Well-Known Member

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    No, quite the opposite actually. Elon, himself, is the one who made the quote about "enough" miles and diminishing returns. He was saying that to satisfy the majority of people a 200-300 mile range car would be fine. He said, that they could make a 500 mile range car now but the cost and added weight, when you typically aren't going to use that range, makes it not worth it.
     
  6. ccutrer

    ccutrer Active Member

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    Okay 8%. That's still 8%, not the nearly 50% you're claiming jumping from 200 to 300 just by tweaking the motor.



    Isn't that what I just said? Instant high torque at low speeds means great for towing, and great for acceleration.
     
    • Like x 1
  7. EaglesPDX

    EaglesPDX Member

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    It is 8% demonstrating small change in the motors has big effect on range. If Tesla further reduces motor size it could maintain the 5,000 tow rating and gain the range that is the most important feature for people buying EV's.
     
  8. JeffK

    JeffK Well-Known Member

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    #108 JeffK, Jul 6, 2016
    Last edited: Jul 6, 2016
    Where does this 8% come from and how do you know it's not due to the power balancing which is done between front and rear motors in software in the dual motor setup?

    Let's examine range per charge from the widget on the Tesla website.

    60 vs 60D at 65mph at 70 degrees.
    Range is 219 vs 225

    225/219 = 1.027 so 2.7% turn the AC on and it drops to 2.4%
     
  9. ccutrer

    ccutrer Active Member

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    And here's the delusion. You have no evidence that the existing differences between a performance motor and a regular motor is "small". And if a similar (or 4x) "decrease" will give you a linear graph increasing range. And if lowering the torque so much to get better range would even allow the car to achieve highway speeds.

    Remember, a Model S 60D, 70D, 75D, and 90D all have the same motors. It's more power from the battery that allows the 90D to have better acceleration. The P90D has a much larger motor, sacrificing weight and/or efficiency for a bit of range.
     
    • Like x 1
  10. ccutrer

    ccutrer Active Member

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    Here let me help: 0-60 acceleration - My Nissan Leaf Forum

    A Nissan Leaf. Respectable EV, but much smaller battery than a Tesla. 0-30 times matching premium cars. After that, it peters out, and can't make it to 100mph --- ever. Comments say they feel power was being limited even at low speeds. A bigger battery to get more range would inherently allow more power. And it's not like Nissan was optimizing for speed. In order to build a viable EV for range, you get acceleration as a side effect. Artificially stunting the acceleration would maybe allow more range - if you're okay with a top speed of 40mph!

    Range, top speed, and acceleration are all positively correlated on an EV. Sure you can still make minor trade offs to get a bit more performance in exchange for range (a P90D), but that's less than 10%. To push performance further, you need a bigger battery, which increases your range. Or you need multiple motors to be able to even apply more force to the axles and the road. Which again gives you better range by only applying force usefully. This is in contrast to ICEs where generally better performance requires a negative correlation with efficiency. They can't control where the force goes, and have a very narrow range of optimum efficiency. So outside those ranges, there are huge amounts of waste. Multiple gears attempts to adapt that small range of efficiency to a larger range. EVs don't need them (or the decision has been made that the additional complexity isn't worth the gains). Did you know the original Tesla Roadster was supposed to have two gears, so that it could have awesome acceleration and a higher top speed? But they kept tearing the gears apart when shifting, so they just shipped them software locked to a single gear.
     
  11. Garlan Garner

    Garlan Garner Banned

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    Delusions?
    I suppose I'm above average - because I need it. . LOL
    I know....that the answer for me is YES. thank you very much Tesla

    Pardon the interruption, but I need to raise my hand again and say.....YES!!!!!

    What kind of language is this that you speak. I don't understand a word of that sentence. I would give up both my trunk and my frunk if that could allow me 2 additional motors. Hmmm what's a word for... double Ludicrous?

    Towing? If I tow anything....its going to be my broken heart if this car is slow and lethargic.
     
    • Love x 1
  12. Garlan Garner

    Garlan Garner Banned

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    I like you JeffK. I love those numbers. Sub 4? excellent. Can I hear 3?
     
    • Like x 2
  13. JeffK

    JeffK Well-Known Member

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    This is actually a misconception that runs rampant on these forums. You don't need a bigger battery capacity to push performance. You simply need a higher amp draw, better cooling. This is simply the way Tesla has marketed the cars. The larger capacity battery packs happen to have higher voltage.

    Compared to a P90DL the Zombie 222, for example, has much quicker acceleration (sub 2 second), much faster top speed (177mph+), and the battery capacity is very small. It can provide 400v at 3840 amps for 10 seconds.
     
    • Like x 1
  14. zenmaster

    zenmaster Member

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    So perhaps you meant to say, are you going to drive the car hard or not?
     
  15. EaglesPDX

    EaglesPDX Member

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    Your dishonest post No. 111 above contains no quotes from me but rather fictional quotes you made up and attribute to me. That you need to lie and then respond to your own lies, the old strawman argument, demonstrates even you think your views have no basis in fact so you create fictions.
     
  16. SpiceWare

    SpiceWare Member

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    Say what? #111 contains a bunch of quotes from ccutrer, not you. Not only does each quote begin with ccutrer said:, but you can click on the red arrow to get back to ccutrer's post:
    Screen Shot 2016-07-06 at 1.16.14 PM.png

    Is your browser hiding that or something?

    The @EaglesPDX is in the original post as ccutrer directed that reply to you, though it only shows up one time and not before each statement.
     
  17. ccutrer

    ccutrer Active Member

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    You are completely correct. To get more performance, you need more power (as in, rate of delivery of energy). Power (in Watts or Kilowatts) is volts times amps. So to get more power, you need to raise either voltage or amperage. You can raise voltage by having a differently designed battery chemistry (like a Zombie 222 as you mention), that can push energy out of the battery faster. I'm not a battery expert, but I expect that different battery chemistries have different properties, including discharge rate, and longevity at different discharge rates. The other way to get more overall power (and the basis for the misconception/simplification) is by adding more of the same battery cells in series to raise the voltage, or more in parallel to raise the amperage. As I understand it (again, not a battery expert), the Tesla batteries are a constant ~400V, and they vary amperage to draw power in and out. Up to absurd amperages - my power meter on Model X 90D goes up to 300kW - which is 750A (300,000/400). To put that into perspective - a VERY LARGE home has a 400A service (at 240V). Most newer homes have a 125A-200A service. And you are almost never anywhere close to a full draw on that. I'm guessing 350-400V DC must be some sort of sweet spot for some reason, cause my solar panels with power optimizers (SolarEdge) work at 350-400V, and the Tesla PowerWall is also in that same voltage range.

    tl;dr: no, you don't necessarily need a big battery to be able to get power out faster. But having a bigger battery does mean the ability to pull power out faster - if you have larger wiring to handle more amps, and a motor that can take more amps and/or volts.
     
  18. JeffK

    JeffK Well-Known Member

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    the 90 kWh (and 85kWh) battery is 400V and I know the older 60kWh battery was only 350V. I'm not sure about the newly released one.
     
  19. ccutrer

    ccutrer Active Member

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    So small differences, but still in the same ballpark.
     
  20. ccutrer

    ccutrer Active Member

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    Holy freaking crap! 3840A?! I didn't even see that number at first glance. The whole point of Ludicrous is to replace a fuse to be able to safely carry more amperage between the battery that can produce it and the motor that can use it. But even that is only like 1700A, isn't it? I suppose for a time limited burst it's doable, but for a continuous draw I can't even imagine how thick of a cable you would need!
     

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