How Does an Electric Car Work? (Electric Car 101)

How does an electric car work? Source: mini.co.uk

Key Takeaways

• Electric cars take in energy from a charging station and store it in batteries that power electric motors to turn the axles and propel the vehicle. Scroll down to see “how does an electric car work” from charging to driving.
• Electric motors power the vehicle, while regenerative braking captures that energy when braking and feeds it back into the battery. Explore the main parts that work together in the background to keep an electric car moving.
• Visit My Tesla Accessories and view our full range of Tesla Model 3, Highland 2024 and Model Y accessories. Available for shopping in Brisbane or delivery across Australia.

1. How Electric Cars Work?

1.1. Powering Up the Vehicle

Once the driver hits the start button, the electricity from the battery, usually composed of lithium-ion cells, flows to the motor instantly and primes the vehicle for driving.

Whereas conventional gasoline cars are combustion-driven, electrical vehicles (EVs) are totally driven by electricity. The battery also stabilises the voltage in the electric system. It acts as a buffer in case of changes in voltage for a steady supply to the different parts of the vehicle.

How does a electric car work? Overview of the internal motor system of an electric vehicle. Source: ev-lectron.com

1.2. Energy Flow from Battery to Motor

While the electric vehicle is started, direct current (DC) power is drawn from the battery and supplied to the inverter. The inverter then inverts it into alternating current (AC) for the electric motor. This AC provides a magnetic field inside the motor, where it twists the rotor to provide the mechanical energy needed to move the wheels and advance the vehicle forward.

The inverter feeds electric current from the battery to the motor. Source: industrial.panasonic.com

1.3. Acceleration and Speed Control

The motor speed is achieved by changing the current that passes through it, and it becomes effective by controlling the frequency of the AC supplied by the inverter.

This process strengthens or weakens the magnetic field inside the motor, affecting its rotation speed and, ultimately, the vehicle's speed. A high amount of current generates a strong magnetic field, and thus the motor rotates faster.

Acceleration is the time in seconds it takes for an electric car to accelerate from rest to 60 miles per hour. An electric car accelerates much faster than conventional gasoline vehicles because instantaneous torque serves where the motor powers wheels directly, and there is a reduction in the number of moving parts.

1.4. Regenerative Braking and Energy Recovery

Coming to “How do electric cars work?” The next major factor that we need to understand is energy recovery and regeneration.

Each time an internal combustion engine vehicle brakes, all its kinetic energy is converted to heat and dissipated through braking force. In contrast, an electric car can recover part of such energy through regenerative braking and put it into useful work.

More specifically, when the driver presses the regenerative brake, the motor works as a generator by toggling the function, hence converting the kinetic energy of the car back into electrical energy and storing it in the battery for temporary maintenance of its charge and reducing the frequency of charging, hence increasing the battery life.

Regenerative braking system in an electric vehicle. Source: e-vehicleinfo.com

1.5. Charging the Vehicle

Charging the vehicle can be started by correctly orienting the charging cable to the on-vehicle charging port and then connecting it to an appropriate power source, such as a wall outlet or charging station. Power on the charger to begin charging, following all instructions given by both the vehicle and charger manufacturers.

When it would take only about 30 minutes to fill an empty 60kWh battery of an electric car using a typical 150kW fast charger, this very charge would take about 8 hours while using a 7kW public charger and roughly about 3 hours using a 22kW charging point.

2. Key Components of an Electric Car

Now that we have come to know “how do electric vehicles work?” it is time to go deep into the details of various electrical components working together to make this mesmerising movement possible.

2.1. Electric Motor

Electric motors work on AC; hence, an inverter is required to convert DC from battery to AC. Source: auto.economictimes.indiatimes.com

These are basically electrical motors that provide mechanical power to an electric vehicle by converting electrical energy taken from the battery of the vehicle into mechanical energy, which, in turn, again drives the car forward.

In contrast to a conventional gasoline engine, where fuel is burned to produce power, an electric motor uses electrical energy to create rotational force. The force is then transferred via the drivetrain to the wheels to move the vehicle.

There are generally two types of motors: alternating current or AC and direct current or DC. Owing to the fact that AC motors may have higher power capacity, larger load capacity, and easier control, they also happen to be more common in electric vehicles. DC motors, on the other hand, are quicker in acceleration and found in older or smaller electric vehicle models.

5.2. Battery Pack

The typical location for mounting the battery packs is at the bottom of the frame of the electric vehicle. Source: able-electrician.co.uk

A battery pack is a source of electricity for the electric motor as an accumulator and provider of electrical energy. Usually, a rechargeable battery is composed of many small cells assembled. The capacity of the battery determines the driving range of the electric vehicles. In addition, the deliverability of electricity determines the vehicle’s performance.

Li-ion-type batteries are the most applied in electric vehicles. Under research, lithium-ion batteries offer the highest specific energy density, up to 220 Wh/kg, and the longest charge cycle life of up to 2,000 cycles, among all-electric vehicle batteries.

2.3. Power Inverter 

Power inverter of electric vehicles. Source: conti-engineering.com

The inverter is basically the device that converts the DC electricity fed from the battery pack to AC, which is suitable for an electric motor. It does so by onboard DC electricity and on/off-switching of the DC voltage many times by means of special electronic switches called transistors. In this way, such a switching action creates a train of pulses whose average value approximates a waveform.

More specifically, besides this, it is the power inverter that controls the speed and pattern at which these switches act. This has enabled it to vary both the output AC voltage and frequency. It thus ensures that AC power is delivered to the motor at its given requirements for effectiveness.

2.4. Charging Port

Electric cars are charged through the charging port. Source: blog.evsolutions.com

Electric vehicles are designed to be charged through a charging port, usually found on either the front or the rear of the car. This, in turn, enables the onboard battery pack to receive energy from external power sources known as electric vehicle supply equipment (EVSE), which is normally referred to as a charging station.

Fundamentally, charging happens when EVSE is plugged into the charging port on the vehicle at home or hooked to a commercial charging station. In all, there are three common electric vehicle chargers:

• Level 1 Charging: It makes use of a normal 120-volt outlet without any sort of special equipment and generally offers the slowest rate of charging, going for about 2 to 5 miles of range per hour. 
• Level 2 Charging: It uses a 220- or 240-volt outlet, which requires special equipment since the higher voltage would be hazardous otherwise. This level could be significantly quicker, adding anywhere from 10-25 miles of range per hour to most models on the market today, supporting all battery electric vehicles.
• DC Fast Charging: This category of EVSE converts the AC into DC electricity and feeds the DC supply directly to the battery pack for fast charging in 15 - 45 minutes. Unfortunately, this works only with specific plug-in vehicles.

2.5. Regenerative Braking System

The regenerative braking system creates electricity any time the driver takes their foot out of the accelerator or hits the brake pedal by running the electric motor in reverse mode. The kinetic energy in motion inside the vehicle then converts into electrical energy, returning to the battery for recharging.

This process to recover lost energy from regenerative braking will add a couple of miles to the battery's charge and extend the operating range of an electric vehicle. It also extends the general efficiency of the car by recovering energy that is usually lost, hence increasing the overall effectiveness of the system.

3. Frequently Asked Questions

3.1. What is the physics behind electric cars?

They are all about the physics of electric motors, the use of electrical energy to generate mechanical energy through the action of magnetic forces on wires carrying currents. In other words, inside the magnetic field, these motors have loops of wire. When an electric current is passed through those loops, the magnetic field begins to apply torque and hence turns a shaft that propels the vehicle.

3.2. Do electric cars need oil?

No, electric vehicles do not need oil changes like conventional vehicles because their engines have fewer moving components than internal combustion engines and, therefore, do not need to be lubricated with engine oil. Instead, most rely on sealed bearings or grease for lubrication.

3.3. How far can an electric car go?

Now, electric cars can cover up to 150-300 miles after charging once and, therefore, are considerably enough for regular drivers and daily commuters.