Just what is an electric car and how does it work?

Although most of us probably think of the electric car as a relatively new development in motoring, in fact it has been around for a long, long time.

Electricity was often used to power early cars, with the first Porsche-designed car being electric and built in 1898.

Electric cars have come a long way since 1898, but the principle remains the same; store electricity in a battery and then use the stored electrical energy to drive a motor for propulsion.

Now, whilst many vehicle owners will be familiar with how a petrol or diesel engine works, you may be wondering how an electric car moves.

It's a lot different to an internal combustion engine (or 'ICE'), so let's start with the basics of how electric vehicles work.

What's In An Electric Car?

If you lift the bonnet (or hood) of an ICE powered car you'll see a mass of plastic, rubber and metal components all inter-twined and full of oils and fluids.

Do the same on an electric car and you'll probably see storage space and little else.

That's because electric cars typically only have around 80-90% of the components of an ICE powered car and most are hidden from view.

What drives an electric car typically comprises:

• A battery pack under the cabin floor to store electricity to power the vehicle.
• An power inverter to change the direct current stored in the batteries to the alternating current typically required for the motors in modern electric cars.
• An electric motor on the front and/or rear axle to drive the vehicle (electric vehicles are often four-wheel drive).

The rest of the components needed for an ICE powered vehicle, such as the air intake/radiator grill, radiator, fuel mixing system, engine, exhaust, starter motor, gearbox and transmission, simply aren't required in an electric car.

Here's what you usually get instead:

How Do Electric Cars Work?

With an internal combustion engine you:

• Fill it with fuel
• Mix the fuel with air and set fire to it
• Use the resulting explosion to drive a block of metal called a 'piston' down a cylinder
• Turn the downwards movement of the piston into circular movement of the wheels using a transmission and gearbox

In an electric vehicle the concept is broadly the same - fill it with fuel, discharge the fuel to a motor and use the spinning of the motor to drive the wheels.

However, with an ICE vehicle a lot of the fuel energy is wasted generating heat during the explosion, discharging the heat through a cooling system and transmitting the engine power through linkages to the wheels.

As a result, the overall efficiency of the engine isn't great.

In addition, a lot of harmful gases are discharged when the fuel is burned, such as carbon monoxide ('CO'), carbon dioxide ('CO2') and oxides of nitrogen ('NOx').

With electric cars the power stored in the fuel (in other words, electricity in the batteries) is sent straight to the motors.

What Difference Does This Make To Electric Cars?

Electric cars don't usually have gearboxes in the sense of a typical ICE car's 4/5/6 speed manual or automatic gearbox and transmission system.

The motors in an electric car or van are typically attached directly to the axles or with a small number of connecting cogs, so there's far less energy lost transmitting power to move the vehicle.

Not only that, electric motors develop their maximum turning power the moment they begin to spin.

As a result, EVs have proportionately faster acceleration than equivalent ICE powered vehicles.

However, all that electricity still has to get to the batteries in the first place and to do this many power stations burn fossil fuels such as coal and gas with harmful emissions like those of petrol and diesel engines.

Electric cars do, though, have a way of regenerating some of the battery energy 'lost' when moving.

The braking systems in EVs are designed to recapture some of the energy applied in braking in order to recharge the batteries.

We've put together some data on the comparative acceleration of ICE and electric cars.

Take a look at our performance league where you can search for car acceleration times, power and more.