What is an electric car?

What makes an electric car different from a petrol or diesel one? We make things clear...

There are several different classes of electric vehicle, but arguably the easiest one to remember is the battery electric vehicle (BEV), otherwise known simply as an electric car.

In the first nine months of 2019, 25,097 electric vehicles had been registered in the UK; a rise of 122.1% compared to the same stage in 2018. While electric cars still represent a small fraction of the overall car market on these shores, demand is rising rapidly, and there isn't a single carmaker that isn’t either making a range of electric vehicles or is looking to do so in the near future.

With the UK Government recently announcing that it intends to ban the sale of diesel and petrol cars by 2040, the industry is now moving towards electric vehicles. But what is a battery electric vehicle and, more importantly, how does it work?

How does an electric vehicle work?

The biggest difference between an electric vehicle and a normal diesel or petrol car is that, in an electric vehicle, the internal-combustion engine has been replaced with either one or multiple electric motors, plus a large lithium-ion battery pack.

An electric car is driven by the electric motor(s), and in the same way a regular engine uses diesel or petrol as fuel from a fuel tank, an electric motor consumes electricity that has been stored in a battery pack.

Lithium-ion cells are by far the most common found in electric cars: these store electricity obtained from the grid by charging through a cable. Much like charging a mobile phone, an electric vehicle is plugged into the grid, through either a home wallbox or a public charging unit, which boast higher power outputs that shorten charging times.

The power from the battery is delivered to the electric motor via its controller, which in turn is connected to the throttle. The amount of throttle movement determines how much power the controller sends to the motor, which then determines how fast the car moves.

Most electric vehicles also come with regenerative braking technology. With this, lifting off the throttle forces the electric motors to, in effect, run in reverse, recovering energy that is then converted into electricity and transmitted back into the car’s battery. The force of this technology has the effect of slowing an electric car down, and on some cars - such as the Nissan Leaf - it's strong enough to bring the car to a complete stop. Nissan calls its version the 'e-Pedal': the blanket term is 'single-pedal' driving, and cars that offer it can be driven almost entirely without using the brake pedal at all.

Unlike normal cars, electric vehicles do not feature a gearbox with multiple gears. This is because an electric motor delivers its maximum torque immediately, and doesn’t need to be revved. Electric cars also come with a much larger working range than those with internal combustion engines, and thus they don’t need gears to optimise performance and economy.

Advantages of electric vehicles

Electric vehicles have many advantages. The two big ones are much cheaper running costs than internal-combustion cars and zero tailpipe emissions. The first of these comes from the fact that electric vehicles don’t rely on diesel or petrol as their fuel, but on electricity, which is much cheaper.

While a litre of petrol or diesel costs on average £1.30, electricity costs just over 14p per kilowatt-hour. And although litres and kilowatt-hours aren’t directly comparable, you can compare the cost per mile to see just how efficient an electric vehicle is.

A full charge of the Kia e-Niro - which has a 64kWh battery - should cost around £9: with a range of 282 miles on paper, this works out at three pence per mile. In contrast, an equivalent petrol or diesel car would cost some 12p per mile, which means you could save £27 for every 300 miles of driving.

Over the course of a year, that really adds up. According to the Government’s Go Ultra Low campaign, owners reported annual savings of over £3,000 in running costs and tax receipts.

The second advantage is the lack of tailpipe emissions. While normal cars emit carbon dioxide, nitrogen dioxide and other harmful pollutants, the tailpipe emissions from electric vehicles is zero. Not only does this improve air quality in busy city centres, but it also means owners of electric vehicles don't pay any vehicle excise duty (VED), or road tax.

Electric vehicles are also exempt from other taxes such as the London Congestion Charge, the recently introduced London T-Charge and the Ultra Low Emissions Zone payment. And in 2020/21, company-car Benefit-in-Kind tax on electric cars will fall to 0%, potentially saving thousands.

Another point many owners make is that electric vehicles are often more enjoyable and peaceful to drive thanks to their lack of engine noise.

Disadvantages of electric vehicles

One of the big concerns for any potential electric vehicle owner is how far they can drive, or the electric vehicle’s range. Early models had less than 100 miles of real-world range, often inducing a condition known as ‘range anxiety’ in drivers.

While electric vehicles such as the 62kWh Nissan Leaf e+ come with a lab-tested range of over 239 miles, which translates into around 210 miles in real-world driving. That’s still far less than what conventional diesel and petrol cars can achieve.

More expensive models like the Jaguar I-Pace and the Tesla Model S come with 250- and 300-mile-plus ranges, but these vehicles cost significantly more than a more conventional electric vehicle such as, say, the new Renault ZOE.

Another disadvantage is the charging time. A full charge on a standard, 40kWh Nissan Leaf takes over 13 hours using a normal, three-pin plug. Even with a 50kW fast charger, it will take over half an hour to charge the car. Conversely, a petrol or a diesel car is far quicker to fill up.

Pros and cons

Whether an electric car is the right car for you is ultimately for you to decide. But it’s worth considering the following points. What kind of a car do you need? Do you do a lot of driving daily? Is your commute something that could feasibly be covered by an electric vehicle?

Also consider whether or not you have the facilities and space to charge an electric vehicle at home. After all, current estimates show that 90% of all electric vehicles are charged at home. Do you have a garage or a driveway where you can plug in an electric vehicle? Could you install a home wallbox charging unit? These will help speed up the charging.

Owning an electric vehicle can be a very positive experience and improve your motoring life significantly. Just make sure you’re prepared to take the plunge.