Everything You Ever Wanted To Know About A Tesla Vehicle

4 months ago by EVANNEX 25

Tesla Model X

Tesla Model X

ENGINEERING 101: TESLA ELECTRIC VEHICLE TECH EXPLAINED [VIDEO]

We Teslaphiles are familiar with the cool attributes of electric vehicles – the instant torque, the greater efficiency, the regenerative braking – but how many of us really understand how all that stuff works? Anyone who’d like a little deeper understanding of the workings of an electric powertrain, without going to school for engineering, would do well to watch “How does an Electric Car work?”

*This article comes to us courtesy of Evannex (which also makes aftermarket Tesla accessories). Authored by Charles Morris.

Tesla

What’s really inside a Tesla Model S (Source: Tesla)

Part of Patreon’s Learn Engineering series of videos, this ten-minute powertrain primer is very accessible but surprisingly informative. It uses language simple enough for anyone to understand, but goes into considerable detail about the workings of an electric drivetrain, and how it differs from its internal-combustion counterpart. If you struggle to explain the advantages of going electric to your car guy friends, this would be a handy video to share with them.

Above: A quick, informative video tutorial on how the all-electric Tesla Model S is engineered (Youtube: Learn Engineering)

Using clear and effective animation, the presentation takes apart a Tesla Model S to demonstrate the workings of the induction motor (invented by Nikola Tesla, it inspired the company name), inverter, transmission, differential, battery pack and regenerative braking system. The general concepts discussed apply to any electric vehicle (EV), although there are some differences (for example, most other EVs use larger rectangular battery cells instead of cylindrical cells).

Tesla

Tesla uses over 7,000 of Panasonic’s cylindrical 18650 battery cells inside the floorpan of the Tesla Model S

There’s a detailed explanation of the differences between an electric motor and an internal-combustion engine (ICE). The latter is far more complicated – it requires a crankshaft with counterweights to translate the linear motion of the pistons into rotational motion, a flywheel to smooth power output, a DC motor for starting, an alternator to charge the battery, a cooling system, and a host of other gadgets that an electric motor doesn’t need. An induction motor, which produces direct rotational motion and uniform power output, is much smaller and lighter. Tesla’s induction motor puts out 270 kW of power and weighs 31.8 kg, whereas an ICE that produces 140 kW of power is going to weigh around 180 kg.

Tesla

Tesla Model S (Image: Tesla)

And of course, the ICE produces usable torque and power only within a limited range (typically 2,000-4,000 rpm), so it needs a complex transmission to connect it to the drive wheels. An induction motor is almost equally efficient from zero all the way up to around 18,000 rpm. Like most EVs, Model S uses a simple single-speed transmission. The induction motor’s smooth power curve, with no interruptions to shift gears, is what gives EVs their delightful performance.

Tesla

Schematic of a Tesla Model S (Image: Cliff’s Riffs via Wired)

EVs do have a few components that ICEs lack. An inverter is needed to convert the DC current from the battery pack to the 3-phase AC used by the motor. The inverter also controls the speed of the motor. Tesla’s ingenious battery pack uses around 7,000 little Panasonic cylindrical battery cells. This allows metallic tubes filled with glycol coolant to snake through the gaps between the cells, keeping the battery cool and extending its life. Battery packs are necessarily large and heavy. Tesla turned this into an advantage by making the pack flat and mounting it at the bottom of the chassis. This gives the vehicle a low center of gravity, which greatly improves handling, and avoids the need to cannibalize passenger and cargo space (a sore point with “non-native” EVs, those that were adapted from ICE vehicle designs).

*Editor’s Note: EVANNEX, which also sells aftermarket gear for Teslas, has kindly allowed us to share some of its content with our readers. Our thanks go out to EVANNEX, Check out the site here.

Tags: , , , , , , , , , , , , , ,

25 responses to "Everything You Ever Wanted To Know About A Tesla Vehicle"

  1. Mister G says:

    MODEL 3 MODEL 3 MODEL 3

  2. Driverguy01 says:

    Funny thing is, even in the rendering the panels alignement seem off. The reflections dont look good between the doors and front fenders.
    Aside from that, it’s a good informative video for those who don’t know the tech.

    1. ffbj says:

      It’s an animation.

    2. Foo says:

      The frunk is also depicted as much roomier than it actually is. (Near the end of the video.)

      They also keep saying “ice-y cars”.

  3. SparkEV says:

    “An induction motor is almost equally efficient from zero all the way up to around 18,000 rpm”

    Not true. Tesla motor starts tapering power around 5500 RPM, or about 45 MPH. At higher RPM, you also have more losses.

    1. Doggydogworld says:

      It’s actually torque that starts to decline around 35-45 mph. Power holds steady until 70-80 mph in the older models, even higher in the later performance models.

      1. Bill Howland says:

        Efficiency drops too, especially compared to his SparkEV. The extremely high-speed/high pole count (4) of the Tesla Induction motor results in poor power factor at high speeds- resulting in more losses in all components (battery, inverter, motor stator and rotor).

        One point ‘slipped over’ in the video, is that some excitation (motoring) from the inverter is necessary before regeneration can occur. Otherwise, unlike SparkEV’s car, nothing would happen when slowing down. Turning the power off with an induction motor elminates the magnetic field.

        The other efficiency comparison between and ICE and an electric motor is a false comparison as I’ve mentioned dozens of times before since the ICE is a PRIME MOVER, and the motor is not.

        Its not a silly distinction either – some people with high utility costs have wondered why their car fueling bills have actually gone UP after trading in their ice car for a BEV. To leave it out of the discussion is a deception for the neophyte.

        1. Mark.ca says:

          “some people with high utility costs have wondered why their car fueling bills have actually gone UP after trading in their ice car for a BEV.”

          Are you ok, Bill? You seem to bring up the silliest arguments lately.

          1. Bill Howland says:

            What exactly have I said that is in error? Do you have a point to make or do you just make silly ad hominem attacks feigning concern for my heath.

        2. G2 says:

          Koo koo.

          1. sven ¯\_(ツ)_/¯ says:

            You dumb dumb.

        3. Jason says:

          I don’t really understand the ICE is a prime mover and motor isn’t comment, please explain?
          Petrol is the energy source for ICE, no petrol then no action. Also, pour petrol into the ICE and it will do nothing, you need to do something to get it going.
          Motor use electricity to get action. Hook up the Correct electrical supply and the motor runs. Try it with a simple motor, 2 wires and a 9v battery, about as simple as it gets.
          So I don’t understand the statement. Engine or motor on their own do nothing. Motor can run with essentially the most basic parts, but engine needs a whole lot of things to be true before it does anything at all. But at the end of the day they both convert one form of energy (petrol or electricity] into mechanical energy.
          Probably a different thing, but the only Prime Mover I know is the tractor part of a semi trailer, once an electric one is made does it no longer be a prime mover?

          1. Bill Howland says:

            Yes I agree with you, you do not understand it.

            The problem with these efficiency comparisons is they are not comparing the same things. There is a chain of events which must occur from the source of the fuel to finally spinning the wheels of a car.

            The ICE accomplishes far more of the processing required than does an electric car. The EV must have this processing done elsewhere. I’m on my 5th EV and for the vast majority of time, my cars run on sunshine – but there is no way I’d state the efficiency is 70% or 90% or some other high number. Its actually less than 10%, but that is ok since the Sun is prolific, and it shines on my roof regardless if it is doing useful work or just wearing out the shingles.

            Whereas you can put plain old #2 fuel oil in a VW or Diamler vehicle and move the wheels directly. Yes the #2 fuel oil was minimally processed and transported to the car from crude oil in the ground, but not much percentage wise.

            I have a friend who makes bio-fuel from left over restaurant oil which requires some processing, and another friend who’s 20 year old Mercedes runs on the french-fry oil directly.

            WIth my electric cars, I’m using as ‘direct’ as source as possible to make them run, (I’m not really dependent on anyone else to make things work), but that is not the case for everyone. Most depend on a utility that does plenty of front end processing work.

            Perhaps the most efficient EV there is gets its initial power from these huge 20,000 horsepower wind mills that have efficiencies around 40-50% – right up there with the highest ICE or Hydrocarbon efficiencies using combined cycle technologies. (63% at the central station, and then not too much loss to get it to the home or business for charging).

        4. Roy_H says:

          Well, maybe I am dumber than I think but the most often mentioned advantage is lower fuel costs. So what is the significance of PRIME MOVER that I fail to appreciate, and why does this make it more expensive?

          1. Bill Howland says:

            Lets take GM cars that I am familiar with as an example:

            My Volt-like ELR Gets around 38 miles per gallon, and also coincidentally goes around 38 miles if I’m doing highway driving on one battery charge.

            It takes more electricity from the wall socket to charge the battery than the listed battery capacity is since there are heating losses when charging the battery – takes about 15 kwh to go from dead to full.

            Gas is cheap at the Indian Reservation, so I pay about $2.50 a gallon to go 38 miles.

            I run up my electric bill 15 kwh to also do the same thing in the same car totally electrically, so with a marginal cost of 12 cents per kwh, it costs $1.80 to go the same distance it does for $2.50 using gasoline.

            Keep in mind GM cars are very efficient with their use of electricity, and there are some makes and models which are quite inefficient in their use of electricity, at least until very recently.

            Now If I lived in NYC , as commenter SVEN does – it is ALWAYS cheaper for him to use gasoline in his VOLT since he pays almost triple what I do for electricity.

            One California commenter stated he was very surprised after purchasing a BEV to find how much his electricity bill went up. There, they have ‘tiered rate structure’ that punishes customers for using too much juice.

            It starts at around 13, but then gets bumped up to around 40 cents / kwh if you use too much, which buying an electric car pushed him over. Now yes, there are separate electric car rate schedules and things in California, and time-of-use, but its not always clear-cut how to get savings. Or, you may get tolerable rates for your EV but then pay through the nose for your other usage..

            So for me (If I didn’t have solar panels), EV operation is cheaper in moderate weather. In the winter time, using gasoline in the same car is FAR CHEAPER, since the heat is free when running in gasoline mode, but when running in EV mode the heater uses at least as much as the rest of the car, on average. It is mandatory to use the heater because in humid buffalo the windows will immediately ice up if u don’t use a heated defroster.

            So under ideal conditions, or when gasoline is $8-$12/gallon as it is in Europe, then even their pricey electricity is almost always cheaper. But in the states EV’s wont have much of an advantage, if any, as long as gasoline is so cheap as it is right now.

            The Prime Mover comment just affects the efficiency number in the video – its not really talking about cost of operation, but as you can see by my simple examples here, you have to figure out what YOUR personal costs will be by using real world conditions.

    2. Pushmi-Pullyu says:

      SparkEV said:

      “[quote] An induction motor is almost equally efficient from zero all the way up to around 18,000 rpm [unquote]

      “Not true. Tesla motor starts tapering power around 5500 RPM, or about 45 MPH.”

      Thanks Sparky! I did not expect to learn something from a “Intro to Tesla EVs” discussion.

      From what you say, I guess the graph linked below distorts reality by cutting off the right side of the graph. I didn’t realize that 5500 RPMs was only 45 MPH.

      So what is the motor/inverter efficiency at 55, 65, and 75 MPH?

      1. ModernMarvelFan says:

        This is also why Dual Motor car can be more efficient by putting the “less efficiently” geared rear motor to sleep while using the “taller geared” front motor for drive.

        This is also why some EVs can trade off acceleration/top speed/efficiency by play with gearing ratio (single speed).

        That is also why even the super efficient EV still needs multiple gears (2-3) for EV racing…

  4. Bill Howland says:

    Model S and x owners: Doesn’t your air conditioning system run in hot weather when charging at a supercharger?

    1. Huhu says:

      Yes, if you turn it on of course.

      1. Bill Howland says:

        Nope that’s not the point I’m making. My Roadster would turn on the air conditioning when charging to cool the batteries.

        All I’m asking is doesn’t the “S” or “X” do the same thing in hot weather, since this video said it is cooled just by ambient air.

        My Volts and my current ELR had 3 different ways to cool the battery depending on the time of year and the charging rate, one of which is refrigerated cooling.

  5. jim stack says:

    I own a used Tesla S 85. I have 2 Tesla Model 3’s on order.

    A few TESLA FACTS you may not know.

    1-The Model S and X use about twice the electricity to travel as many other smaller lighter Electrics cars. We’ll see how efficent the model 3 is!

    2- If you buy a used Tesla that was in even a minor accident it maybe be a SALVAGE TITLE and Tesla turned off Super Charging for that car. If Super Charging is turned off you also can’t DC Fast Charge at any other locations along with no Super Charging.

    3-Once it is declared SALVAGE they won’t sell you part or work on your car. If you want you can try a $1,200 inspection to get it off their black list.

    4- There are quite a few small bugs and failures in a Tesla. IE The pop out door handles seem to fail and one can cost you $800 or more to fix.

    5- Tesla has a small LEAD ACID starter battery. If that goes low or fails the entire car won’t move or run. You can just start it but you have to open the nose cone to get to the connections. Ground is the frame. A little bolt is the positive. Be careful.

    6- Many other little issues it would take a long time to list.

    I still love Tesla and they are a great car.

    1. Pushmi-Pullyu says:

      Thanks for the caveats, Jim!

      I guess the lesson here is that if you’re considering buying a used Tesla from any source other than Tesla’s CPO program, it’s best to contact Tesla and ask if that VIN number has been blacklisted.

    2. Jason says:

      As regards point 1, I don’t know any other car with a 30kWh battery that can go 200mi. If a Tesla uses about twice the power then a 30kWh car would do 200mi.
      Maybe Tesla Model S uses about 10% More power. Model X is a different class so real comparison, but still not almost twice the power usage.

      1. Roy_H says:

        Tesla Model S mpge 89.
        Chevy Bolt mpge 119.
        Bolt is 33.7% more efficient than Model S.

        1. Nix says:

          Roy_H your numbers are mistaken. The current line of Tesla Model S cars get 98 to 103 mpge.

          Are larger, longer range, higher performance cars less efficient than smaller, shorter range, lower performance cars? Why yes. What else would you expect?

Leave a Reply