How do electric cars work?
Unlike petrol or diesel vehicles, electric vehicles do not require internal combustion engines to operate. Instead, they are equipped with an electric motor and a rechargeable battery pack. Electric vehicles emit fewer greenhouse gases over their lifetime than petrol or diesel cars, ultimately making EVs better for the environment. Research by The European Energy Agency found that even accounting for electricity generation, the carbon emissions of an electric car are around 17-30% lower than those of a petrol or diesel car.
In a simplified version of how EVs work, they charge and store energy in their batteries before supplying power to the motor, which turns the wheels. Many more complex, smaller processes occur, and these will be explored further in this post.
The basic components of electric cars
Several components are integral and unique to electric vehicles, from batteries to regenerative braking systems. Let’s dive in:
Batteries
The idea behind the lithium-ion battery is to move electrons by making a difference in power between two parts: one is negative, and the other is positive. These parts, called electrodes, are in a special liquid called electrolyte. When the battery is used to power something, the electrons gathered in the negative part go through a path outside the battery to the positive part. This is the time when the battery gives power. On the other hand, when the battery is getting charged, the energy from the charger sends the electrons back from the positive part to the negative part. We will be discussing this in further detail later on.
This image is sourced from AutoTrader
Inverter
An inverter transforms the direct current (DC) power into the alternating current (AC) power that an electric vehicle motor needs. The inverter can control how fast the motor spins by changing the frequency of the alternating current. It can also make the motor more or less powerful by adjusting the strength of the signal.
Electric motor
Getting electricity from the inverter, the electric traction motor is what makes an electric vehicle go. These motors usually run on alternating current (AC), which is better and more reliable than direct current (DC). When AC electrons reach the motor through the inverter, they create a spinning magnetic field that makes the motor turn. Electric traction motors are very effective and strong because they don't have multiple gears like a regular car engine. So, when you press the pedal, the power to the engine kicks in almost right away.
Electric powertrain
An electric vehicle's powertrain includes the high-voltage electrical system needed for operation. Typically composed of an inverter, electric traction motor, reduction drive, and traction battery, these powertrains are lightweight, compact, and deliver smooth, instant torque. Many inverters in these powertrains can recover energy during deceleration through a process called regeneration, converting unused AC power during braking into DC power stored in the battery pack.
Regenerative braking systems
Regenerative brakes reverse electric motors, acting as generators to return energy to the hybrid or electric system, extending the vehicle's range. These periodic boosts in battery range contribute to enhanced efficiency with regular use.
Power Electronics
Power electronics convert and distribute electrical power to other vehicle systems such as heating and ventilation, lighting and infotainment. Power electronics components include inverters, DC converters and chargers (for plug-in electric vehicles).
Electric car heaters
A common question is about electric car heaters and how they work - the process is fairly simple. Electricity is run through a conductor to produce heat. Air is then blown through the heating element and into the cabin. The mechanism of cooling and heating systems in EVs is not very different from those found in petrol or diesel cars. The main difference is the power source of the compressor - batteries are used for electric cars.
This image is sourced from City AM
Electric cars have revolutionised the process of changing gears as the engine speed changes because they generate a constant amount of torque across a range of RPMs. This inherent characteristic simplifies the mechanism, allowing the electric motor to directly distribute power to the wheels without the need for multi-speed transmissions or subsequent gear shifts. Meaning, the majority of electric cars are automatic.
How do electric car batteries work?
Considering the main difference between an electric car and a fuel-powered car is the battery, we thought we would give you some details about how they work.
While driving, the battery discharges as electrons shift from one electrode to another, creating an electric current that propels the motor and moves the car's wheels. Recharging the battery, whether at home, work, or a public charging point, reverses the electron flow, restoring the battery's charge.
Even though car batteries have a long lifespan, the ongoing process of discharging and recharging eventually leads to a reduction in battery capacity over time, similar to the way a mobile phone battery degrades.
Different types of EV batteries
There are three different types of EV battery cells: cylindrical, prismatic, and pouch. All three of these batteries are lithium-ion-based with casing. Each battery has a specific chemical composition, size, capacity, and lifespan, making it more or less desirable for manufacturers to prefer one battery over another.
An example of a cylindrical battery - the 2170 cell is typically used for portable use whereas the 4680 cell is used in EVs. Graphic by Jerry Lee.
Cylindrical batteries are the classic version of EV batteries and are made up of lithium-ion batteries with aluminium or steel casing. The cylindrical shape is created by electrodes and separators layered together and then rolled over.
Cylindrical batteries have high-temperature resistance and can be combined to make a strong battery pack. Tesla is an advocate for cylindrical batteries. The production of this type of battery is dependable and experienced, and because the production is standardized, the cost is low for quick production.
Prismatic batteries are also made up of lithium-ion batteries with aluminium or iron casing. These types of battery cells get their shape from layered electrode sheets and separators put into rectangular metal casings. They are the largest EV batteries compared to Cylindrical or Pouch.
Prismatic batteries get their shape from layered electrode sheets and separators put into a rectangular metal casing. These types of batteries have been manufactured for decades and are common in BMWs and Volkswagen. The rectangular shape of prismatic batteries doesn’t leave any gaps when combined with a battery pack.
Pouch batteries are the smallest of the three types of EV batteries and are small in length and weight. They are often used in portable devices like phones but can be used for EVs too. They can fulfil the same power as cylindrical batteries with the same capacity, and because of this, manufacturers may choose these batteries if space is limited. These are still relatively new in the EV battery world, and because of this, pouch batteries often cite the possibility of overheating (otherwise known as thermal runaway).
This diagram shows how pouch batteries look and work inside an EV.
Recovery systems
Recovery systems in EVs recycle the energy normally lost during braking by storing and then using it for acceleration or starting, thus saving fuel and cutting emissions.
Recovery is achieved by raising the alternator voltage when you slow down and brake. This increases battery charging and helps the car slow down.
What is the unit of measurement used with electric cars?
Electric car battery capacity is measured in kilowatt-hours (kWh). The average electric vehicle has a battery capacity of around 40kWh, but it varies between car models and can be from 20kWh to 100kWh. The more kilowatts your battery holds, the longer the driving range and the further you can travel on a single charge. As a general rule, the bigger the battery means the car is likely to be more expensive. It is important to consider what battery capacity and driving range you’ll need before you look to lease an EV.
Charging your EV
You can charge your electric vehicle at home, at work or via the EV charging networks.
Charging your car at home is the most convenient method, providing a sufficient daily driving range for the average driver, especially when done overnight. Home chargers typically provide 7kWh of power. The usual cost for a home charging point is approximately £800, but in the UK, there is a discount program called the OZEV electric vehicle charge-point grant that can reduce the installation cost. All of your questions are answered in our blog: how much does it cost to fully charge an electric car at home?
You can also charge your electric car at work which involves installing electric car charges at workplaces like offices, car parks, factories, or warehouses. This is especially important for employees who may not have access to a charger at their home address. This is a fantastic benefit for employees whilst allowing the company to hit its sustainability goals. You can learn more about workplace charging here.
The final place you can charge your EV is in public. This is the most expensive way of charging your car but can be convenient when on a long journey. These can be found at service stations, car parks, supermarkets, cinemas and on the side of the road. Rapid charging provides up to 80% of charge in as little as 20-30 minutes.
The price of charging your EV does depend on where and where you charge your car. Charging your EV at home does take a longer time but you can plug it in overnight when there is no surge pricing, whereas charging your EV in public will give you 80% in 30 minutes but will cost more.
This image is sourced from Business Green
Common concerns about battery degradation
EV batteries typically degrade because of temperature, cycles and time. Storage and operating temperatures do have a big impact on the lifespan of a battery - warmer environments do negatively affect this. On average, EV batteries degrade at a rate of 2.3% of maximum capacity per year. This means an EV battery should last as long as ICE competitors.
However, for an average EV owner, battery degradation shouldn’t be an issue. The government mandates EV manufacturers to warranty batteries for 8 years or 100,000 miles. Interestingly, Tesla is working towards a goal of the million-mile battery. There are several ways you can elongate the lifespan of your battery - read more in our blog: What is the lifespan of an electric car in the UK?
How do electric car motors work?
As we have established so far in this blog, EVs have motors instead of engines. EVs use both Alternating Current and Director Current moto, and there are several variations of each.
DC Motor
This is also known as the brushed DC motor. The advantage of this motor is its ability to produce high initial torque, whilst also offering easy speed control. A limitation is the brushes and the motor’s communicators which both require a higher degree of maintenance compared to other motors.
Brushless DC Motor (BLDC)
These get rid of the brushes and the communicators, making them more technologically advanced and lower maintenance. They are efficient and offer a higher starting torque. These are usually incorporated into the hub of the wheel, which it drives directly.
Permanent Magnet Synchronous Motor (PMSM)
Similar to the brushless DC motor, the PMSM has permanent magnets embedded into the rotor to create a magnetic field. They have a high power rating and are usually used in high-performance vehicles, like sportscars. These are the motors you would find in a Tesla Model Y.
AC Motor
Two types of AC motors are used in EVs: synchronous and asynchronous. Both types can work in reverse and convert mechanical energy into electricity so it can be stored in the EV’s battery during deceleration - otherwise known as regenerative braking. In an asynchronous motor, the electric-powered stator generates a rotating magnetic field, whereas in a synchronous motor, the rotor acts as an electromagnet.
A synchronous motor is seen as the better option for urban driving where there can be a lot of stop-and-start at lower speeds. In contrast, the asynchronous motor is preferable for driving at high speeds for long periods.
The benefits of electric motors
Electric motors can be used within a much wider speed range than internal combustion engines. Maximum torque is available from a standing start, providing full impressive traction right away. You can read more about the fastest electric cars in our blog.
This explains why models with an electric drive do not need a clutch or a gearbox. Generally, an efficient reduction gear with a fixed ratio (only one gear) is used. Furthermore, as electric machines can move in both directions, electric cars don’t necessarily need a separate reverse gear.
How can electric cars work for you?
Switching to an electric car is one of the most significant ways you can make a positive change to net zero. Many people are limited by information, access, price and complexity.
The major benefit of electric cars is the contribution that they can make towards improving the air quality in towns and cities. Electric cars do not produce carbon dioxide emissions when driving which reduces air pollution considerably.
Understanding the true cost of owning an electric car is crucial before making a purchase. Despite the higher upfront cost of EVs, the overall ownership expenses are significantly lower than those of petrol or diesel cars. To give an idea of fuel versus electric costs - the approximate annual fuel cost for a Ford Focus is £1,230 whereas the approximate cost to charge an EV Volkswagen ID.3 is £630. This means in total you would save £600 every year! You can learn more about how much it costs to run an electric car here.
This image is sourced from MotorTrader.com
Common misconceptions about electric cars include limited battery range, battery lifespan concerns, and limited charging infrastructure. The battery range in electric cars is enough to get you from A to B daily, and the only time this will be an issue is if you’re embarking on a very long journey that exceeds your EV's range; in such cases, you will simply have to charge during your journey. Additionally, there are 55,301 electric vehicle charging points across the UK, distributed across 31,445 charging locations. This represents a 46% increase in the total number of charging devices since January 2023. Consequently, there are numerous opportunities to charge your EV on the go.
Every company in the UK can help their employees on their personal journey to net zero by offering The Electric Car Scheme as an employee benefit.
In this article, we've covered the workings of electric cars, dispelling common misconceptions, exploring key components, and discussing charging options. Additionally, we've highlighted the benefits of electric motors, detailed the types of batteries found in EVs, and explained how they operate.
In the future, we expect to see advancements in the batteries used in EVs. These improvements include energy density, which will lead to longer ranges on a single charge - ultimately making EVs more practical for long-distance travel.
Salary sacrifice makes getting into an electric car easier than ever, because it allows employees to save 30-60% on any electric car by reducing their salary in exchange for an electric car as a benefit. At The Electric Car Scheme, we have a wide range of electric cars available to lease. Browse our quote tool to find the perfect EV for you.
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