Electric Cars – How Do They Work?

At a glance:

• Electric vehicles are rapidly growing in popularity in the UK
• Electric vehicles might look similar to traditional cars, but they run on very different principles
• Find out what makes EVs different, and how electric cars actually work
• Learn the essentials of EV battery technology and motors 

Contents:

• What is an electric vehicle?
• What types of electric cars are there?
• How are electric cars made?
• What are the inner parts of an electric car?
• Key components of an all-electric car
• How does an electric car engine work?
• How do electric car batteries work?
• How does electric car charging work?
• FAQ’S

Are you thinking of buying your first electric vehicle (EV)? You’re not alone. Over 600,000 new EVs were sold across the UK in 2022, according to Zap-Map. Meanwhile, a Which? survey found that 1  in 3 Brits plan to make their next car an electric one. 

Now, if you’ve always driven petrol or diesel cars, you may well have a few questions about how electric vehicles work. The biggest difference, of course, is that EVs use electricity from a rechargeable battery pack to drive them forward, rather than burning liquid fuels as in traditional cars. There are also a few other important differences to be aware of. 

So, how do electric cars work? Let’s get up to speed with the tech. 

What is an electric vehicle?

An electric vehicle is a type of vehicle that is powered by an on-board electric motor which is, in turn, powered by rechargeable batteries. Most people think of EVs as pure-electric, but you can also get hybrid cars which use a mix of battery powered motors and petrol/diesel-powered motors.

While private cars are the most common type of EV, there are several other kinds of vehicle that fit the definition – from mopeds through to vans and even buses.

What types of electric cars are there?

There are several different types of electric cars on the market today. Here are the main ones to consider:

• All-electric: These cars are powered exclusively by an on-board, rechargeable battery that you must connect to a charging point to ‘fill up’. Depending on the size of the battery and the fuel cell technology used, the range – the distance you can drive between charges – varies considerably. 
• Range-extender: These are close to all-electricEVs, but they have a small petrol engine which works as a generator to charge the battery (the petrol doesn’t directly power the motor). These cars aren’t currently on sale in the UK. 
• Plug-in hybrid: These cars are mainly powered by their on-board rechargeable battery, but they have a small petrol engine that can also be used to power the motor. 
• Full hybrid: The motors in these cars are powered by both a petrol/diesel engine and an on-board battery – the car uses clever software to switch between the two motors depending on your needs. The battery gets charged through kinetic energy whenever you brake, not by plugging it into the mains (this is a process known as ‘regenerative braking’ – you could say this is a self-charging electric car). 

Mild hybrid: These vehicles are mainly powered by petrol or diesel, but have an on-board battery that can let the car operate as an EV for short distances.

How are electric cars made?  

At first glance, EVs are made in much the same way as traditional internal combustion engine (ICE) cars. 

First, the car is designed. Then, a skeleton (both the frame and the seats) is built from aluminium. Various metals and plastics are used to build the wheels, steering wheel and other internal parts. The body and the roof are then attached to the frame. EV designers always prioritise the use of lightweight materials, because the batteries are significantly heavier than an ICE engine. 

When we get to the car’s components, things start to get a little different. The manufacturer places a radiator, the electric motor, and air conditioning at the front of the car, under the ‘bonnet’ (whereas in an ICE car, this space is mainly taken up by the large and complex motor). They then place the battery cells all along the floor of the car in a T-shape (with the top of the ‘T’ towards the back, to help with weight distribution). 

Once that’s all wired up, it’s just a case of installing the windshield, checking the wheels are aligned, and fitting all the trim and customisations. 

Key components of an all-electric car

Here are some of the most important components found inside an electric vehicle:

• Rechargeable battery: This is, of course, vital for powering the electric motor
• Electric motor: This is hooked up to the battery pack and drives the car’s wheels
• Charge port: This lets you charge your car up by plugging it into a charger or your mains at home
• Cooling system: This keeps the battery, motor and other electronics at the optimal temperature. It might use liquid cooling or air cooling
• Power electronics controller: This controls how electrical energy flows from the on-board battery to the electric traction motor

Hybrids have similar components but also have an internal combustion engine (which adds a few more parts to the mix). 

How does an electric car motor work?

Electric car engines are much less complicated than the engines in traditional ICE cars that you might have driven before. On a basic level, they receive electrical energy from the on-board battery. The motor then uses this to drive the wheels directly. 

Thanks to this simplicity, you don’t have to shift between gears as you accelerate – plus, electric motors generate torque instantly so you can accelerate faster, and much more smoothly than with an ICE car. An added benefit of this simple motor is that there’s much less that can go wrong – so hopefully, that means fewer trips to the mechanics!

How do electric car batteries work?

Almost all EVs today use lithium-ion batteries. These offer high energy density, while still being relatively lightweight and compact. That basically means you get lots of power while still having a fairly light and small battery.

The principles of an electric car battery are much the same as any other rechargeable battery. Inside each cell, there are two electrodes (anode and cathode), with an electrolyte in between. When you charge the battery, electrons accumulate on the negative electrode. When you drive the car, they pass through the electrolyte to the positive electrode. This releases electrical energy which is used to power the motor. 

The main way of charging the battery is by using an external electricity source, but the kinetic energy that comes from braking and coasting can also ‘top up’ the battery too.

How does electric car charging work?

Now you know how the motors and batteries work, you might be wondering how electric cars are powered. To charge up an electric car, you have three options:

• Using a three-pin plug: Simply plug the charger into a wall socket, and the battery will start to charge. This is the slowest method by far, but is a good option for overnight charging. 

• Using a socketed charger: When you buy your EV, you’ll get a couple of cables you can connect to socketed chargers which are usually wall-mounted. You might find these chargers at hotels, car parks, supermarkets, and can also install them in your home for faster charging. 
• Tethered chargers: You may well have seen these kinds of charging points around town or at motorway service stations. They often have their own cables attached, which plug directly into your EV. 

When ‘filling’ your electric car up, you can also choose different charging speeds. Slow charging will take 8-10 hours, so is best suited to doing overnight. Fast charging takes 3-4 hours – a good option if you have EV charging stations outside your workplace or offices. Then there’s rapid charging, which can charge the vehicle up in as little as 30 minutes. This is a good option if you’re doing a long road trip and need to top up quickly. But remember, if you use rapid charging all the time, it can degrade the battery as it heats up, and this causes small amounts of damage which, over time, mean it charges less well. 

Head over to our electric car charging guide for more in-depth info on charging your EV. 

How do electric vehicles work?

Knowing how electric cars work is really important when you’re deciding whether or not to buy this kind of vehicle. Modern EVs are still relatively ‘young’ technology, and so there’s a lot of development and innovation going on in terms of range, battery power and other technology, as manufacturers explore how to make electric cars more efficient. 

Now you know the fundamentals of how electric vehicles work, read our FAQs, or browse for EVs today.