26 March 2021
26 March 2021
Electric vehicles might seem like far-off, futuristic and fantastical vehicles that will one day be driven by our robot minions while we luxuriate in sci-fi like cabins. But really, they’re not that dissimilar to mobile phones.
It wasn’t all that long ago, that a device as ubiquitous and future-fabulous as Apple’s iPhone seemed unimaginable.
Today, of course, they are everywhere, and you’ve probably noticed that you really don’t have to worry as much as you used to about running out of charge. Early smartphone batteries left you with charge anxiety – would you get through the day, or even the next phone call before you got to a charger?
Electric vehicles will very soon become abundant, with several European countries making pledges to ban the sale of petrol- and diesel-powered cars over the next 10 to 15 years. Batteries are a vital part of what will make electric cars an increasingly central part of our lives, and companies such as Mercedes-Benz are throwing considerable engineering and financial heft behind research to improve their technology.
The different types of electric vehicles
As anyone with a smartphone-owning parent or grandparent can attest, new technology can be intimidating to some folk, even if it’s inherently simple.
The first thing to get your head around is that we have two types of electric vehicles in New Zealand. There are battery electric vehicles (EVs, or BEVs) such as the innovative Mercedes-Benz EQC, which is fully electric; and plug-in hybrid electric vehicles (PHEVs) like the Mercedes-Benz E 300 e, which is powered by both an electric motor and an internal-combustion engine.
Both models use the same type of rechargeable lithium-ion battery, which is popular because of its high energy density compared to weight. Less weight means greater potential range, so the lighter the battery is, the better.
Which type of EV battery is right for you?
These EV batteries are also designed for a high kilowatt-hour (kWh) battery capacity, which means you’ll get more hours of energy out of them, which is important if you want to drive long distances.
The kWh rating will tell you precisely how much power can be stored in a battery pack, but it’s not to be confused with the kilowatt (kW) rating for your EV’s motor power.
The term kilowatts, as with petrol cars, refers to how much power you’re getting from an engine, or an electric motor. Kilowatt-hour refers to battery capacity, and will largely determine how far your vehicle can travel (i.e. the range) on a single charge.
The logic goes that the higher kWh battery capacity the greater the range of the vehicle, but you also need to take into account the kW of the motor and its efficiency. If it’s a high-performance motor it’ll be using up more of the battery capacity, by drawing more power to use for propulsion and acceleration, and thus reducing your range.
It’s pretty important, then, that you figure out exactly what you’re going to want your EV for: will you be driving short or long distances?
Do you want a larger car that will require a more powerful engine, or are you happy with a smaller vehicle (such as the recently unveiled Mercedes-Benz EQA) that requires less power?
By narrowing down your requirements you’ll be able to figure out which type of electric vehicle battery is right for you, which in turn helps you determine just how often you’ll need to hook your vehicle up to a charging station.
And while there are a number of factors that will determine your electric vehicle battery lifespan, current predictions hover between 10 and 20 years.
Cost-wise, replacing a lithium-ion battery currently runs in the low thousands, which isn’t too bad considering the cost of lithium-ion batteries was 80 per cent higher a decade ago. And the price of batteries will only shrink due to economies of scale as more and more cars are fitted with them.
The future of EV batteries
With EVs now clearly the way of the future, a lot of time and money is being spent developing new batteries that will power the vehicles we’ll be driving over the next few decades.
Mercedes-Benz has been actively developing the next generation of electric vehicle battery. It is working on a replacement for lithium while also planning to use silicon anodes instead of carbon, which will reduce CO2 emissions at the point of recycling and increase vehicle range by around 20 percent.
Beyond that there’s solid-state battery technology, which will see liquid electrolytes replaced with solid electrolytes, resulting in a weight reduction and a predicted efficiency improvement of 35 per cent.
Regardless of what’s to come, one thing is clear: EVs are the way of the future, and with more people becoming aware of environmental concerns, you’ll want to stay up to speed.
By Stephen Corby