Motors

  • Motors

  • G Johns

    Member
    January 10, 2022 at 6:46 am

    I just rewatched a video were Steve said the 3 wheel car has been tested with each motor individually used. I hope at certain times when conditions for good traction exsist to just use the rear wheel for motive power and use less than the 100Wh. He said that they hope to be able to have the option to also freewheel the rear wheel so no magnetic drag. That’s great news for me because those are all an options I hoped for.

  • Peter Jorgensen

    Member
    January 10, 2022 at 7:10 am

    What do you mean 100 WH? I don’t understand.

    The battery size is 100 kwh. (Like gallons of gas)

    Each motor has 50 kw of power. (Like horsepower)

    50 kw (kilowatt) of power for 1 hour is 50 kwh (kilowatt-hour).

    100 wh is about the capacity of a handheld battery charger bank for a cell phone.

    • Joshua Rosen

      Member
      January 10, 2022 at 7:23 am

      The stated objective is 10 Miles/KWh which is 100Wh per mile. What G is saying is that he hopes that by just using the rear motor the energy consumption can be reduced still further. Don’t know how much that would help, is it more efficient for one motor to provide all of the power vs two or three. When cruising along at a steady speed, especially with the Aptera’s .13 COD, you won’t need much power, one motor would only be using a fraction of it’s capacity so you won’t need to run more than one motor but is a single motor putting out X power more efficient than two motors each putting out 1/2X or three motors putting out 1/3X?

      Are the Elaphe motors induction or permanent magnet?

      • This reply was modified 5 months, 4 weeks ago by  Joshua Rosen.
  • G Johns

    Member
    January 10, 2022 at 7:31 am

    Mr. Rosen, Yep, exactly. Will be fun finding out what’s better 1/2, 1/3, or 1.

  • Oz (It’s Oz, just Oz)

    Member
    January 10, 2022 at 8:57 am

    Using the rear wheel only would disable the use of torque vectoring in the Aptera.

  • Dean McManis

    Member
    January 10, 2022 at 9:33 am

    Chris did mention that if a motor was not powered it would act as a generator. But even though it would seem that running just the rear motor (on the AWD model) would reduce the energy use, but the powertrain losses are minimal for wheel motors. So having 3 motors use 5kWh each, or one motor using 15kWh to maintain a speed may not be such a great benefit. Chris estimated that the AWD models would consume 10% more than FWD models. It is fun to think about the possibility of additional energy savings, but I think that the gains would be relatively small. Tesla had initially thought that their AWD models would have greatly reduced range having twice the motors. But they said that there was some load balancing that could be done which greatly reduced the overall power usage. Also regen power recovery is higher with all 3 motors in use. I ordered the AWD option because I want the added power and control. Hopefully the extra energy use won’t be that much much.

  • Jose Osorio

    Member
    January 10, 2022 at 12:09 pm

    the amount of energy used to move a vehicle demishes with speed upto a certain point. at a speed of about 60mph an average vehicle requires between 10 and 20hp to maintain its speed and overcome wind resistance and rolling resistance. Considering the 0.13 drag coefficient and sub 2000 pound weight of an aptera it will not be very difficult to move around. One single motor can provide enough power to move the vehicle and reduce some of the losses attributed to heat as the a motor operates. the energy savings can be a very small and still have a large effect on the overall efficiency of the vehicle since just 1 percent savings on a the 100kWh battery can equate to 1 whole KW or 10 miles of driving distance.

    • Francis Giroux

      Member
      January 10, 2022 at 6:35 pm

      Aptera uses 6000w at 60 mph or 100 wh per mile. At 60 mph 6000w is roughly 8 horsepower since one horsepower is 750 watts. Of course using 6000 watts at 60 mph has to be 100 percent efficient to put out those 8 horsepower, and we know no motor and inverter are 100 percent efficient. If I knew that driving with just the rear engine on an all wheel drive would be more efficient that using front wheels on a front wheel drive, I might consider getting the all wheel drive if it included a way to shut off the front motors. Someone mentioned that driving with the rear motor only would cause the front motors to generate electricity. That would only be true if the circuits for the front motors were closed. That’s why you would need to shut off the front motors to take advantage of rear wheel only efficiency. A permanent magnet moving by a copper coil only causes electricity if the circuit of the coil is closed.

      • G Johns

        Member
        January 11, 2022 at 6:06 am

        Mr Giroux,

        I just think it would be fun to, at certain times, be able to just have a pusher instead of a puller. Just something to play with, not for energy use or savings. I know that just only rear wheel propulsion is more dangerous in less than good/perfect road condition so would have to be extra careful when using. But imagine the donuts you can do in a huge fresh snowy parking lot. You can do it without snow but will eat up the rubber tires alot more. I also hope regen is user adjustable because I have a couple long hills I think I would mostly like to coast down or use minimal regen 2%-5% if possible then up to max at bottom. Still keeping the faith for aptera.

        • Dean McManis

          Member
          January 11, 2022 at 8:43 am

          Aptera has said that there will be multiple levels of regen available to select. I also start my day going downhill, and will appreciate the added range that regen provides.

    • Dean McManis

      Member
      January 10, 2022 at 11:33 pm

      I am sure that there will be several Beta Aptera models built and used for battery, motor and software controls testing. It always is a balance between getting the maximum efficiency, practical use, NVH, cooling, reliability and performance. With efficiency being the prime goal for the Aptera, you know that they will test all software, control and motor options to see what gains that they can make in range and energy utilization.

  • Nathan Hubbard

    Member
    January 10, 2022 at 12:39 pm

    If you want to use less energy, just don’t step on it so hard.

    • Francis Giroux

      Member
      January 10, 2022 at 6:59 pm

      I have done many tests on acceleration efficiency in gas powered vehicles and found that full throttle acceleration was actually slightly more efficient that partial throttle if the fuel mixture was at stoichiometric (14.7 to 1), which it isn’t at full throttle because the engine would overheat at full throttle for long periods of time. So EPA allows an extra rich fuel mixture at full throttle.

      With electric cars the power is pretty much proportionate to the electricity used at all throttle settings. Acceleration is just as efficient at full throttle as partial throttle unless the tires are squealing. (I know “throttle” is not the correct word for an electric car but most people think the throttle is the go pedal, instead of the butterfly in the throttle body or carburetor on the engine, so I use the word throttle as most people understand it.)

      In gasoline powered vehicles the real efficiency is gained at the end of a trip or leg of a trip, by coasting to your destination or your next turn, instead of braking. The same would be true in an electric vehicle if we could let the motors free-wheel (open the circuit instead of regen braking), but with regen braking catching some of the kinetic energy and putting it back into the battery (not 100 percent efficient) most people don’t want to waste time coasting, but it would be more efficient to not brake at all (regen or mechanically). If you doubt this, try getting over 100 miles per gallon on any modern vehicle that EPA rates at 40 mpg, highway. Been there, done that.

      • kerbe2705

        Member
        January 10, 2022 at 8:04 pm

        Every Adaptive Cruise Control system I’ve experienced has allowed the vehicle to coast and, in EVs, has employed regen to slow the vehicle to maintain the set maximum speed on, say, a downhill roll.

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