Innovation


Electric vehicle technology explained.

25 January 2021

Get to know the technology powering the electric vehicle revolution with our guide to the different types of all-electric and plug-in hybrid vehicles.

Innovation


Electric vehicle technology explained.

25 January 2021

Get to know the technology powering the electric vehicle revolution with our guide to the different types of all-electric and plug-in hybrid vehicles.

The Mercedes-Benz EQC 400 4MATIC in metallic grey

A 2020 survey by the Electric Vehicle Council found that 56 per cent of Australians are considering an EV, like the Mercedes-Benz EQC, as their next new car purchase. Image: Daimler.

If the number of cars sold in Australia shot up by 200 per cent in a single year, you’d probably notice, not least because it would be extremely hard to find a parking space.

Incredibly, though, that’s how much Australian sales of electric vehicles (EVs) grew in 2019, and chances are you’ll be seeing a lot more of them on our roads in the coming years as we accelerate towards emission-free driving.

The UK government has pledged to phase out the sale of new cars with petrol or diesel engines by 2030 as they move towards a zero-emission transport future. In Norway, where more than 60 per cent of all new cars sold are already electrified, the goal is 2025.

According to an August 2020 survey by the Electric Vehicle Council, the shift in our thinking is already happening, with some 56 per cent of Australians already considering an EV as their next car purchase.

So, what exactly is an EV, and how does it differ from a plug-in hybrid electric vehicle? Let’s take a look at the technology and find out how electric vehicles work.

All-electric vehicles – 100 per cent electric, zero emissions

What you might call an all-electric or battery electric vehicle (BEV) is comparable to a modern smartphone. It, too, uses lithium-ion batteries, which need to be recharged regularly, depending on how far you drive.

A cutaway model of the Mercedes-Benz EQC showing the technical components

An all-electric vehicle uses lithium-ion batteries to run the electric motor, which sits on the axle and turns the wheels. Image: Daimler.

The power from those batteries is used to run electric motors, which sit on the axle and turn the wheels. Some cars get just one motor, but in a vehicle such as the new Mercedes-Benz all-electric EQC, there are two, one on each axle, which provides all-wheel-drive grip and acceleration.

The set-up for EVs is a lot simpler than an internal-combustion engine and requires far less maintenance. Generally, electric vehicles don’t even have gearboxes. There’s just one gear for going forward; to reverse, it’s spun in the other direction.

This absence of gear shifts means EVs have seamless acceleration and can effectively deliver all of their torque from zero revs per minute, leaping away from the traffic lights with urgency, or effortlessly overtaking on the highway.

While the very first EVs were small city cars, modern iterations – such as the Mercedes-Benz EQC – have grown into proper family-sized vehicles, as battery technology improves.

Electric range has also greatly improved; the EQC can take you around 400km between charges. When you consider that most Australians travel less than 20km to work each day, that is more than enough for a week’s commuting.

Cleverly, electric vehicles also recharge themselves as they drive, through a process known as “regenerative braking”. As soon as you step off the throttle of the EQC, the motors start providing stopping force, and recharging their batteries. The more often you stop, the more regen effect. So stop-start traffic is actually a good thing, for once.

Perhaps most importantly, EVs like the EQC have no exhaust pipe, so they produce no emissions of any kind while driving, which is why so many people believe they are the way of the future.

Plug-in hybrid electric vehicles – The best of both worlds?

The biggest challenge in persuading people to buy EVs in a country as geographically spread out as Australia is range anxiety (the fear of running out of charge and being stranded).

The Mercedes-Benz EQC can go long distances before you need to recharge, and Australia’s largest public EV charging network, Chargefox, now has more than 2,300 stations dotted around the country.

There is another option, however, that can remove range anxiety, reduce emissions and deliver the benefits of both electric and petrol technologies in one vehicle.

It’s called a plug-in hybrid electric vehicle, or PHEV, and it’s a technology that’s available in vehicles of various sizes and shapes, from a sporty hatch like the Mercedes-Benz A 250 e, to luxury sedans like the C 300 e and E 300 e or even an SUV like the GLC 300 e.

A picture of the Mercedes-Benz A 250 e

Plug-in hybrid electric vehicles are available in a range of shapes and sizes, from a sporty hatch such as the Mercedes-Benz A 250 e right through to SUVs like the GLC 300 E. Image: Daimler.

A PHEV brings the best of both worlds by having both an electric motor and battery that can be charged using a cable, just like a full EV, as well as a petrol engine.

The GLC 300 e, for example, can run for 40km in pure-electric, zero-emission mode – meaning you could make a typical commute on the electric motor and just recharge every night. For longer trips, you can switch to the 2.0-litre four-cylinder turbo-petrol engine, fill up with fuel and drive as normal.

Cleverly, PHEVs also offer a mode where you can combine the power and torque of both the electric system and the combustion engine for truly thrilling performance.

In the Mercedes A 250 e, you can get more than 60km of pure electric range, and also sporty performance, with a 0 to 100km/h dash of just 6.6 seconds.

By Stephen Corby