What does ‘range’ mean for an EV? When is ‘range anxiety’ misplaced?

If you are thinking about getting an electric vehicle, what should you not be anxious about and what should you actually worry about?

Spanning Florida’s sawgrass wetlands from Naples on its west coast to Fort Lauderdale on the Atlantic, the Everglades Parkway tests the mettle of electric vehicle owners as they traverse the 130-kilometre highway at high speed.

“We do the trip in our Genesis SUV with the cruise control set at 99 m.p.h. (159 km/h), while our friends follow in their Tesla. By the end of the trip, the electric car is eating itself,” says engineer and entrepreneur Tom Wittenschlaeger, disparaging the EV’s capacity to travel long distances with the airconditioner cranked.

“The last few miles to the charging station is a white-knuckle drive for our friends,” he says, given that the route offers scant charging opportunities between the two coastal cities. Ominously dubbed Alligator Alley, it’s an obstacle to EV ownership, notes Wittenschlaeger, himself CEO of a start-up EV-maker (Ayro).

In these angst-ridden times, “range anxiety” is a worry many consumers don’t want foisted on them. It’s defined as the fear of running out of power without access to a charging station in time to replenish the EV’s battery.

The dread of being stranded is one of the biggest roadblocks to the adoption of EVs — almost half prospective buyers cite it as a concern — rooted in the long-held perceptions of early EVs’ minimal range.

“Imagine that the fuel tank in your car was shrunk down from 45 litres to 15 and that gas stations were as sparse as EV fast-charging stations are today. Wouldn’t you experience range anxiety?” asks professor Olivier Trescases, director of the University of Toronto Electric Vehicle Research Centre.

“The good news is that the range in EVs is getting better with every new generation, and both governments and automakers are making massive investments in fast-charging infrastructure,” Trescases says.

The question is whether we really need 600 km, or even 1,000 km, of range, given that a tiny percentage of trips would require that amount of energy … and the massive batteries needed to store the electrons.

What is the optimum range for Canadian EVs and how many charging stations do we need?

The answer, as usual, is: It depends.

Canadians want different options that suit their needs and budget, just as they do with gasoline-powered vehicles.

A Toyota Corolla’s four-cylinder engine has an effective range of 400 km between fill-ups, given that most owners won’t let the tank fall below one-quarter full. Its meagre range has not prevented the Corolla from being the world’s bestselling auto, with more than 50 million cars sold to date.

Prospective buyers are full of questions when they kick the tires on an EV. Range-related queries include: “Can I trust the range estimate that the on-board computer provides?” and “Will I be stranded on road trips?”

“The accuracy of the range displayed on the dash has greatly improved in the latest models,” Trescases says. “The on-board routeplanners guide you to the nearest charging stations. If you get stranded, it’s no longer a last-minute surprise.”

In Canada, the climate affects EVs. Things change in frigid weather: “For those with very long commutes in remote areas, EVs are simply not yet viable for the winter,” Trescases cautions.

That’s because lithium batteries have an optimal temperature range similar to humans, he points out. At very low temperatures, the electrochemistry is sluggish and the available power is heavily restricted. For example, maximum acceleration is reduced until the battery pack warms up.

“The battery is less efficient at very low temperatures and the heating systems eat up more energy, which reduces the range considerably,” he explains. Conversely, at high temperature, the battery can experience faster degradation (a long-term effect of excessive fast charging), and the range is also limited by the heavy use of air-conditioning.

“It’s important for drivers to understand that the temperature of the battery is not the same as the outside temperature. The battery is liquid-cooled and -heated, and carefully regulated to stay within an optimal range,” Trescases says.

To help consumers understand how much energy their EV is using and to express this in recognizable terms, Canada devised the Le/100 km or “litres of gasoline equivalent per 100 kilometres” measure of energy consumption. This aims to strike an apples-to-apples comparison. To derive Le/100 km, you calculate how many litres of fuel would contain the same energy needed to drive 100 km in the EV, using the energy content of gasoline: one litre equivalent to 8.9 kWh of electricity.

The published rating for each EV model considers different speed profiles that correspond to urban and highway driving as they affect energy use. An EV with a 2.4 Le/100 km combined city/highway rating is the equivalent of 117 miles per imperial gallon of gas.

“Electricity is still relatively cheap, compared to gasoline. Many EVs can recharge from empty overnight for under $10,” Trescases notes. Charging at home offers the best value, especially now that Ontario offers an ultralow overnight rate of 2.4 cents per kWh to homeowners who choose that option. However, fast charging at commercial stops can cost $20 to $40, although this still represents significant savings over a tank of gasoline.

Trescases says research and innovation in battery chemistry will bring about further improvements in EV range, although each new breakthrough brings trade-offs between variables such as energy, power, cost, safety and lifespan.

“The challenge with many of the new battery architectures has been low ‘cycle life’ — that is, the number of charge-discharge cycles the battery can handle without losing significant energy capacity — as well as the ability to fast charge, not to mention quality-control challenges for mass production.”

U of T’s Electric Vehicle Research Centre is investigating multichemistry battery packs that combine different types of chemistries to harness the best of different worlds: for example, using high-energy batteries for long range, and high-power batteries for acceleration and strong regenerative braking.

So, where are we at with EVs? In entrepreneur Tom Wittenschlaeger’s opinion, they work best in urban environments, not on continental highways. The former nuclear engineer came up with the Ayro Vanish, a low-speed electric truck that can make inner-city deliveries with no tailpipe emissions. Given the current state of battery technology, it’s the best application of the tech at a sensible price, he argues.

Says Trescases, of U of T: “The battery breakthroughs will come, but we don’t need to wait for that. We need to target the low-hanging fruit in transitioning away from fossil fuel transportation as quickly as possible.

“That starts in the suburbs of the major cities, where public transit remains inadequate, while the population density is high, the power grid is strong and the travel distances are manageable.”

Pedal-to-the-metal sprints through Alligator Alley may have to wait for more advanced battery chemistry, coming soon.