How Much Battery Does Your EV Really Need?汽车专题
Invariably, a customer considering an electric car - any electric car - will ask a simple question, albeit sometimes a little crudely phrased: how big is the battery?
Since an EV's battery size directly correlates to how much energy can be stored within and, therefore, the range yield one can expect the car to travel for without needing to be plugged in again, this is of course a valid question.
CAPACITY = Weight = Volume = Range = PRICE
Its battery size, or capacity, typically measured in kilowatt-hours, also tends to dictate any EV’s price, making it an even more pertinent question to ask. None of these were ever a concern with combustion-powered cars in the modern era since petrol/diesel filling stations were well scattered throughout the road network and stopping for a full tank took but a few minutes.
With the advent of electric vehicles, prior concepts about ‘refuelling’ need to change writ large as ‘charging’ entails so many other variables, not least of which is whether the electrons are coming via an AC charger or a faster DC charge source - and if so, at what rate (how fast)?
Eventually, society will also have to come to some common agreement as to how much battery - or range - we need from our EVs so that it could perhaps be made a standard or unwritten (but widely understood) expectation.
This is because the majority of us cannot be expected to have one city-bound EV with a more modest battery capacity (and therefore cheaper) and another one waiting for us to require a lengthy road trip that utilises its large battery (making it more expensive).
At this extreme, we find such vehicles as the GMC Hummer EV which is confirmed to have a massive 210kWh battery that takes 1,013-litres of space and weighs 1,325kg on its own - about that of a Honda Civic.
A 'Standard' Minimum Range Expectation?
It follows that such a vehicle would need a very powerful and energy-demanding electric motor setup just to get moving let alone keep up on the highway and deliver decent range. This is a prime example of how an EV powertrain’s efficiency decreases past a certain point (like a bell curve) no matter how much ‘more battery’ is thrown at the problem.
Mazda with the MX-30, MINI with the Cooper SE, and the Honda e all have around 35kWh to spare, taking them to roughly 200km on a single charge or thereabouts. They are all definitely among the most modern EVs offered by each of these automotive brands but you neither would classify them as ‘flagship’ vehicles in the same vein as the Lucid Air (up to 118kWh), Mercedes-Benz EQS (up to 120kWh) that push the boundaries in terms of range, luxury, performance, or all three.
Range anxiety - how much range is enough range?
However, those aforementioned non-flagship cars have all come under criticism that their batteries are too small to alleviate the effects of ‘range anxiety’, but it does demonstrate an important conclusion that automakers are, simultaneously yet independently, arriving at. A balance.
This is an equilibrium between the cost of manufacturing an EV (to which its battery is the largest, heaviest, most expensive component), the cost customers would willingly pay for such a vehicle, their range expectations, and - most importantly - their actual range requirements as proven by data.
We, for our part as car buyers, just have to get used to the fact that we typically don’t need as much range as we think we do in real-world driving.
Passenger cars spend 90% of their existence in parking
Remember, your vehicle spends the huge majority (above 80%) of its time parked and unused. Therefore, as charging infrastructure improves and we can more easily access a plug point or charging station, the worry about depleting any EV’s energy reserves below, say, 40% becomes narrower and narrower.
Though that might be true in 10 years, those of us living in 2022 are being asked to just trust in the growth and development of that infrastructure. It’s like being hungry and only being served appetisers while the main course sits baking in the oven. You know it’s coming up, and you hope it’s as tasty as promised.
Still, perhaps automakers need to set their sights higher. That 200km offered by the Mazda, MINI, and Honda might never be deemed enough no matter how robust the charging network gets. Perhaps a more acceptable figure is at least 300km on a fully charged battery, regardless of the EV’s actual kilowatt-hour figure.
There will be exceptions, naturally, such as the single-seat micro-EVs that are really meant for short-throw commutes and little else. However, if the majority of electric cars on sale to customers looking to switch from a car with an internal combustion engine, provides the assurance that each will be able to reliably take them continuously for at least 300km could be a powerful motivator and increase EV adoption to that coveted tipping point.
A little unexpectedly, it is sister car brands Hyundai and Kia that has seemed to have struck the most holistic balance of range, weight, cost, and performance. Take the IONIQ 5 and EV6, for example, both of which are built upon the same EV-specific vehicle platform and offer varying configurations/variants for range and performance.
Can We All Agree?
Neither of them features lithium-ion batteries that dip below 58kWh or exceed 77.4kWh, which can still be considered rather modest. Yet despite that limited matrix, variants within both models are able to offer a range of at least 350km and up to claimed 490km (Hyundai IONIQ 5 Extra Long Range) while another is capable of a 3.5-second sprint to 100km/h that can rival supercars (Kia EV6 GT).
This seems like the right mix that satisfies the automaker’s need to maintain a healthy profit margin, keeps the ecological footprint and supply chain demands in check, while also maintaining the customer’s expectation of range/performance that does not deviate too far from what is/was offered by combustion cars.
Others take a different view, arguing that there is “no ideal size” such as Professor Olivier Trescases, the Research Chair in Power Electronic Converters and director of the University of Toronto EV Research Centre, who adds “…what we expect in the future is a wide variety of options from automakers,”
“You really have a hard limit on the weight and volume. The whole point of this shift in transportation is to reduce emissions. It’s quite emissions-intensive to make batteries in the first place,” emphasising that consistency is more important that reducing size as it pertains to the goals of EV battery technology.
As unrealistic of an expectation as it is (at least given the current tech available), Deloitte’s 2022 Global Automotive Consumer Survey revealed that Canadians want an EV with range of at least 600km. Beyond North America, if this ‘expectation’ is reflective of a wider car buying population in other modern societies, that’s clearly going to be a problem….