How Electric Cars Work: An Engineer’s Explanation


Electric cars are becoming more and more popular by the day. They function similarly to a gasoline vehicle but without all the harmful gasses leaving the exhaust pipe. You will hear them referenced as an EV or an Electric Vehicle when talking with professionals or at a dealership.  

So how do electric cars work? Electric cars work by converting electricity (potential energy) into kinetic energy, which puts the vehicle into motion. Batteries provide the storage space for electricity in these vehicles that are then used to propel the motors. The motors then turn the wheels at varying speeds depending on the input from the accelerator pedal.

There are many significant things that dictate whether the electric car works or not. And they are very different than regular, internal combustion cars. But, not all electric cars are created equal. In this article, we will go over how the most efficient electric cars work and why they work the way they do. 

How The Drivetrain Of An Electric Car Works

Most EVs you can charge in the comfort of your own home. They require a specific charger that is given to you upon purchasing the car. But, only use chargers produced by the manufacturer of your Electric Car. If you use other brands they can damage the battery system costing tens of thousands of dollars. 

Once charged, the batteries are used throughout your commute to work, soccer games, or back home after a busy day. The instrument cluster in front of the steering wheel will show you a range or the distance you can travel at your current battery levels. 

The batteries transfer the stored electricity to motors that then transfer power to the transmission. The transmission in most electric cars does not have more than 1 gear. This is very different from gasoline vehicles. This special transmission design is a key in the power and torquey feel you get when driving an electric car. We will dig deeper into this later. 

 Electric cars have a cooling system to keep the battery packs, computer modules, and other key components from overheating while in use. Driving aggressively can cause the batteries to drain faster. This can also affect the temperature at which the system operates. The cooling system will push the electric water pump harder, to work that coolant through the system faster to keep from overheating. The radiator fans will turn on as well to provide some extra cooling. Electric cars do a very good job of making you aware when you are punching them and when you are being economical with your driving habits. 

Electric cars can give some a sense of anxiety called Range Anxiety. This is because some of the automotive industry has painted a picture that chargers are not readily available and you will be left stranded in the desert. This is simply not the case, we are in 2021, not 2002! Electric cars have proven technologies that will not leave you stranded. There are sensors in place that monitor the health of the car and will display messages if there is anything out of specification. One message you won’t receive is to add power steering fluid.

How The Power Steering Works On An Electric Car

The next time you open the hood on an electric car I’d like for you to try and find a belt. You probably won’t! Electric cars do not have a serpentine belt that drives any kind of pumps, there is no need for timing belts or chains, and the steering is all-electric. Motors are the way that electric cars can have many features found on a gasoline car without all the belts.

The steering rack is designed very similarly to a normal one, but the way it works is it has a motor that transfers power to the rack. It uses power from the battery packs to use this function. This power is measured by a sensor in the steering wheel that applies resistance to allow it to feel similar to normal power steering. This would then lead you to think well if there are no belts, there’s also no vacuum to run the brake system, right?

How The Braking Works On An Electric Car

Without a source of vacuum pressure coming from a gasoline engine, Electric Car engineers needed to find a way to make it work differently. Electric car brakes work by using an electronic brake controller. It sends signals to an actuator that regulates the hydraulic pressure sent to the brake calipers that then slow down the car. This is not the only way to slow down an electric car though!

Most electric cars have a feature called regenerative braking. This allows the motors to assist in slowing down the car when coasting or coming to a stop. Doing this creates heat inside of the motors and that heat can be used to maintain the charge or even charge the electric batteries. This is a very efficient way to stop the car and keep your batteries charged. This also preserves your brake pads and rotors on the hydraulic side of the braking system as you do not need to use them as often. 

It can take time to learn how the regenerative braking system slows down the car. It provides a sense of a heavy drag on the car and can even bring the car to a complete stop when timed correctly. This handy feature still needs hydraulic brakes to make any sudden or emergency stops to prevent a collision.

To keep up with a modern sense of style electric cars will have an electric parking brake as well. No more yanking up the plastic brake handle with the little button on the top in the middle of the console when you want to drift a corner in the snow! The parking brake is a button that is pressed only when at a complete stop. This could also remind you that the A/C doesn’t need a vacuum system, but it would need a belt to operate too right?   

How The A/C Works On An Electric Car

The A/C system works by electric motors as well. Electric cars can have cool air by using air compressors that compress the air, using these electric motors. When using the A/C system, the electric batteries keep the energy flowing to the compressor. 

It is a much quieter application as well. The compressor will kick on but since there is no hydraulic clutch you will not hear the clunkiness of a hydraulic air compressor kick on when turning on the A/C in an electric car. The control modules inside of the car will let the A/C compressor know when to turn on and then it cools the air, when needed, without the added noise. The future is quiet! That is until you pull up aside a 400 horsepower of pure American muscle. 

How Are Electric Cars So Much Faster Than Gas Or Diesel Vehicles?

So, you’ve got your A/C on in your electric car, cruising around town, and then it happens. You are at a red light, not making a single noise. You just used your regenerative braking to get you a little extra charge when a loud, obnoxious, V8 muscle car pulls up next to you. Now to some, this is not intimidating at all as you are just driving from point A to point B, but to others, this is the moment you’ve been waiting for! 

Electric cars are powerful and very torquey cars. When fresh off the charger, or after doing a full day of driving with 25% battery left, you have instant power, but how? 

The battery packs are a huge part of this. Electric car batteries range from 20kwh to 100kwh (kilowatt-hours). The more kilowatt-hours, the more power you can put down to the pavement. Let’s review where the power goes after the battery, and that’s to the motors, and then to the 1-speed transmission, and then directly to the wheels. Gasoline cars transfer the power from the engine with many moving parts to the transmission which also has a lot of parts, then to the driveline. Power is lost amongst all these moving parts in a gasoline car. 

This brings us back to that glorious 1-speed transmission. An electric motor can spin very fast, much faster than a gasoline engine. Once the engine reaches peak RPM, the transmission will shift to another gear to protect the engine from exploding and allow it to accelerate safely. Electric motors do not need these extra gears because there is no engine holding it back. The motors spin fast enough to get up to speed with one gear! The 0-60 times in some electric cars are at the supercar level because of the power distribution and how efficient they are. 

So when that moment happens, make sure you are buckled up. You’ll know all your power is going to make it to the pavement. Take them out to the track and that poor person next to you is going to wonder why they lost. Now you can tell them. 

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