How Do Electric Cars Work?

We take a look at the ins and outs of electric cars, from how they work to how much they cost to charge up and run.

Young girl with sunglasses on charging her red electric car whilst looking at her mobile phone
19 Sep 2023

You’ve almost certainly heard that the future of driving is electric cars. You’ve probably seen a Tesla out on the roads or one of the many other types of electric cars that are becoming ever-more popular. But how much do you know about them, and how do electric cars work?

Although the inner workings of an electric car may baffle us, they’ve actually been around for much longer than you may realise.

Electric cars have been around since the 19th century, predating even the famous Ford Model T. They were used as taxis, and by the start of the 20th century, there were more than 30,000 electric cars on the road. However, advances in internal combustion engines made petrol-powered cars cheaper and easier to run, so electric cars faded into the background.

That’s all changing now, though, as environmental concerns and improvements in electric car technology are causing big changes in our driving habits.


How an electric car works

So, how do electric cars actually work?

Today, electric cars run on batteries and an electric motor rather than an internal combustion engine vehicle, which runs on petrol or diesel. As electricity rather than fossil fuels power them, they're much better for the environment.

Whereas traditional engines need fuel to work, electric motors need charging. To gather the electrical energy they need, they must be plugged into a charging point. This electrical energy is then stored in rechargeable car batteries in the vehicle, which power the electric motor to allow the car to move.

How far you can drive with an electric vehicle depends on the battery size and capacity. Battery capacity is measured in kilowatt per hour (kWh) – so typically, the higher the capacity, the further the range.

One major difference in driving an electric car is that most have an automatic transmission rather than a manual one. While fuel engines need to move up through gears to achieve maximum power, electric motors have instant and consistent power with just a single gear.


Electric car components


With an electric car, not only do you have to get used to not having a gearbox or clutch pedal, but you’ll also have to become familiar with what’s under the bonnet.


One of the first things you may notice, and one of the main benefits of an EV, is that they generally have fewer moving parts than a standard car, which typically means EVs require less maintenance.


So, just what are the components of an electric vehicle?


Electric motor – Instead of a fuel engine, an EV has an electric motor. The car battery supplies power to the motor, which helps turn the wheels and move the car.


Converter – Most electric cars have a DC/DC (Direct Current) converter which converts the higher-voltage DC power from the battery to the lower voltage needed to run many of the other electrical components in an EV, such as radio, air conditioning, etc.


Transmission - EVs have a single-speed transmission, sending maximum power from the motor to the wheels with just one gear.


Battery –The electricity that powers the vehicle comes from the battery. Battery capacity is measured in kilowatts per hour (kWh).


Battery pack – As well as the battery, there’s also a traction battery pack that helps store electrical energy.


Charge port – An outlet where you plug your car battery into an electrical power supply to help charge it.


Thermal system – Helps the car maintain a safe operating temperature so that it functions optimally.


Power electronics controller – Manages the flow of electrical energy, controlling the speed and power of the electric motor.


Onboard charger – Converts incoming AC (Alternating Current) electricity from the charge point and converts it to DC power to help charge the battery.


EV Batteries explained


Electric cars have a battery pack, made up of lithium-ion batteries, or cells, that helps store the electrical energy needed to power the car and its motor and any other onboard functions, such as the radio.


Just like a mobile phone battery, EV batteries need to be charged to work, and the way you charge them is to plug them into an external power supply.


How long EV batteries take to charge depends on your battery’s capacity and the type of charger you’re using. Car batteries are measured in kilowatts per hour (kWh) - this is how much energy they need in to charge fully. The higher the battery capacity, the further you can drive on a single charge. For example, some cars have a range of about 145 miles, while others may be able to go 350 miles without being charged.


Batteries in modern electric cars tend to last around 10 to 20 years before they need replacing.


How to charge an EV


To charge your electric vehicle, you’ll need to plug it into a socket or charging unit either at home or in public.


At home, it is possible to use a standard domestic three-pin plug, which usually has a capacity of just 3kWh. However, it’s inefficient to charge EVs this way as it takes a long time, typically anywhere from 8 to 10 hours, to fully charge.


Alternatively, you can have a charging point, also known as a wallbox, installed at home, which gives out a more powerful 7kWh. This is also the charging speed and capacity you’ll find at charging stations in most supermarkets and public car parks. Charging times vary depending on the battery capacity of your car but typically take 3 to 4 hours to charge.


There are many public charging points available throughout the UK, although you’ll have to pay to use them. Public charging points are available at service stations, supermarkets, business car parks, and motorway services. These charging stations either offer a standard charge rate, as mentioned above, or can provide a fast or rapid charge. A rapid charger can deliver about 43 kWh and takes roughly 30 minutes to an hour to charge most compatible vehicles.


Types of electric cars


Not all electric cars are created equal – some are fully electric vehicles, while others still rely on traditional internal combustion engines for power.


Here are the three main types of electric cars:


All-electric – Also sometimes referred to as plug-in electric, all-electrics are zero-emission vehicles as they run entirely on electricity– no petrol or diesel engine required. These use battery packs to store the electrical energy required to power the car.


Plug-in hybrid – These vehicles run mostly on electricity, but they also have a fuel engine, so you can use petrol/diesel to power the car if your battery runs out of charge. These cars can be plugged into an external power supply to recharge the battery, just like all-electrics, but they also take fuel. Plug-in hybrids tend to produce lower emissions than standard vehicles depending on how frequently you’re operating the vehicle in electric mode.


Hybrid-electric – In hybrid-electrics, you’ll find an internal combustion engine and one or more electric motors. These cars can switch between fuel and electricity to power the vehicle but tend to run mostly on fuel. These cannot be plugged into an external power supply to charge them.


How do hybrid cars work?


As hybrid cars are not all-electric vehicles, you may be wondering how hybrid cars work. Well, put simply, hybrid cars have an internal combustion engine and one or more electric motors.


Although they can be driven in electric mode, they still rely heavily on petrol or diesel. They cannot be plugged into a charging point– the only way they charge is through regenerative braking (when the energy normally lost during braking is captured and stored to be used by the electric motor) or when the internal combustion engine is running.


There are two types of hybrid vehicles – mild hybrids and full hybrids.


Mild hybrids use a battery and an electric motor to power some of the vehicle, and they allow the fuel engine to shut off when the vehicle stops (for example, at traffic lights), but they cannot operate fully on electrical energy alone and so still need petrol or diesel for power.


Full hybrids, however, have larger batteries and more powerful electric motors, which can power the vehicle for short distances and at low speeds. Full hybrids tend to be more fuel efficient than mild hybrids.


Do electric cars charge while driving?

At the moment, electric cars can’t charge while driving, this is only possible with hybrid cars that can charge up electric motors while they are being driven by the internal combustion engine. Electric cars can only be charged when plugged into a charging station. However, there are certainly plans in place to develop this kind of technology, so watch this space.


How much does it cost to charge an electric car at a public charging station?

How much it costs to charge an electric car at a public charging station varies depending on several factors, such as:

  • The network you’re using, as some may cost more than others.
  • Whether you’re using a pay-as-you-go charger or you pay a subscription fee– it can sometimes cost you less to charge your car if you have a membership with a particular network.
  • Whether you’re using a standard, fast, or rapid charger. Although rapid chargers charge quicker, they are typically more expensive to use.
  • Some public chargers, such as those found at supermarkets or your workplace, may offer free charging for customers and employees.
  • The capacity of your battery – larger batteries tend to take longer to charge and, therefore, may cost you more to recharge.



What happens when an electric car runs out of charge?

When an electric car runs out of charge, the same thing happens as when a petrol or diesel engine runs out of fuel – the car stops running. However, you’ll be notified well before you run out of charge, as most EVs have a warning light or message that pops up when you’re running low and tells you how much range you have left.


How do electric cars work and charge?

Full electric cars work by using electrical energy that is stored in batteries. This energy helps power the electric motors, which turn the wheels to allow the vehicle to move. Electric cars charge when plugged into an external power supply, either using a home charger or public charging station.


Do electric cars lose charge when parked?

Electric cars lose a very small amount of charge when parked, as there are some onboard electric systems that still require a low amount of energy even when the car is not switched on. If you’re planning on leaving your car for a long period of time and are worried about the battery depleting, there are things you can do, like switching to energy-saving mode and turning off any unnecessary pre-set features, to conserve as much electricity as possible.


Can you push an electric car if it runs out of power?

Yes, you can push an electric car if it runs out of power. However, it’s important to bear in mind that without power, steering your vehicle will be much harder – just like any car.


Can you jumpstart an electric car?

Technically, you can jumpstart an electric vehicle. If your battery is dead, you’ll need to find where it’s located in your car and use a battery starter to boost it with appropriate jump leads. You should not use another electric vehicle to jumpstart your car as it can put the onboard electronics at risk of serious damage. When you jumpstart, make sure the car is not plugged into a charger and only connect to a charger once the car has started and jump leads have been disconnected.


Just like mainstream vehicles, electric cars must be insured in order to ensure safety on the roads. When it comes to car insurance, UK providers will offer a range of policies to suit every preference. Compare car insurance quotes here.


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