How long does it take to charge an electric vehicle? The question is more complicated than it seems, and that's a challenge for the auto industry.
Vehicles have different battery sizes, and charge at different speeds. The same vehicle at different chargers will experience wildly varying charge times.
And no matter what charger a driver uses, an electric vehicle requires a change in habits. That may be an obstacle for automakers who need to persuade sometimes skeptical car buyers to try their first electric vehicle.
Most owners charge at home or at work. The process takes hours, which might sound like an unbearable hassle to owners of gas-powered cars. But for current owners it feels much more convenient than a gas station trip because they're doing other things — in many cases, sleeping — while the battery recharges.
The slowest way to charge is on a standard 120-volt outlet, which adds just a few miles of range per hour.
"I don't have a driveway or a garage so I have to run an extension cord," says Andy Fraser, who parks his Volkswagen e-Golf on the street and plugs it in to a normal household outlet. It takes him 12 full hours to add 50 miles of range.
But 50 miles is all Fraser usually needs. And his car would be parked overnight anyway, when he usually does his charging.
"No big deal," he says.
The next step up is a 240-volt level 2 charger. The speed varies, but 15-25 miles added per hour spent charging is typical.
David Cooper, who drives a Nissan Leaf, used to charge on a standard outlet at work, but persuaded his condo building to add two public level 2 chargers.
"The vast majority of the charging I do now is at home," he says. He plugs his Leaf in overnight, and schedules it to charge between 2 and 6 a.m. In those four hours, it adds around 100 miles of range.
Many shared chargers at workplaces, restaurants and other public locations are level 2 chargers, but they can also be installed at private homes; the cost can range from a few hundred to a few thousand dollars.
Clemens Mendell is a realtor and puts a lot of miles on his Tesla Model X. But no matter how much he drives in a day, his car is ready for him the next morning.
He plugs into the level 2 charger in his garage when he gets home, and the car waits to charge until his electricity rates drop to their lowest levels overnight. The vehicle only spends about three hours actually charging.
He usually sets it to stop charging at 70%, which is better for the battery and provides more than enough range for his daily use.
"Every day I'm leaving the house with a full tank of gas, so to speak," he says. "I certainly don't miss the dirty handles at the gas station and the smell and all of that."
That's a common sentiment from current electric vehicle owners, who describe home charging as a perk — and that's before you consider that home charging is considerably cheaper than paying for gasoline. But for would-be buyers, those lengthy charge times can sound alarming.
And convincing car shoppers that they'll learn to love the charging cable is absolutely essential for the auto industry at a time when mainstream automakers — not just Tesla — are betting big on electric vehicles. General Motors now says the future will be "all-electric," and it's not alone.
"[Over] this next five year period, automakers are investing $234 billion into electric vehicle platforms and parts and plants," says Mark Wakefield, managing director at the consulting firm AlixPartners. "One-fifth of their investment budget is going towards electric vehicles at the moment, and growing over time."
For that bet to pay off, a lot of mainstream car buyers, including people who don't have a strong preference for an electric vehicle, will need to be convinced to plunk down money for a battery-powered car.
Governments have a vested interest in pushing this change to reduce carbon emissions and fight global warming. But buyer preferences are crucial, too. To win over skeptics, automakers have aggressively increased vehicle ranges — the average is now 250 miles, Wakefield says, and rising rapidly — and they're working to bring vehicle prices down to be competitive with gas-powered cars.
But charging times are another potential roadblock. And it's not just home charging. Two words loom large in would-be buyers' minds: road trips.
For trips that involve hundreds of miles in a single day, drivers typically rely on DC fast chargers. These chargers — which are much more expensive to install, and thus rarer — use direct current, rather than alternating current, to charge much more quickly.
Confusingly, not all DC fast chargers are equally fast. A 50kw charger is on the slow end of the scale, while next-generation chargers boast 250kw or 350kw capabilities — well beyond what most vehicles are currently capable of accepting.
And comparing speeds is difficult because chargers work very quickly on a depleted battery, but slow down as the battery approaches full.
But generally speaking, a fast charger can fill most batteries to 80% in less than an hour, and sometimes in less than half an hour. It's harder on a battery and more expensive than charging more slowly, so most drivers typically only use them when they're on lengthy trips.
Joyce Breiner recently visited a Tesla Supercharger at a Sheetz in Gettysburg, Pa., to add more juice to her Tesla Model 3. Tesla has been upgrading its proprietary charging network, and this brand new supercharger was able to add around 160 miles of range in 25 minutes, for about $11.
"I'm going to probably go into the Sheetz ... and get a drink and maybe a snack," Breiner said.
That kind of charge speed is exceptionally fast for most vehicles on the road right now.
Whether it will be fast enough to convince electric vehicle skeptics to make the switch remains in doubt.
"Until you reach parity with what everyone is used to ... call it five minutes to fill up your gasoline vehicle, you're still now basically bringing something that's less attractive to people," says Mike Dovorany, a vice president at the market research firm Escalent.
Companies are working to install more super-fast chargers and to build vehicles that are capable of handling that type of charging to help assuage those concerns.
It's an uphill battle, Dovorany says, because people tend to overweigh the potential negatives when they think about making a change to their habits — even if fast charging could be a relatively small part of their life as an electric vehicle owner.
Dovorany says once people own an electric vehicle, they find a lot to love: electric cars are powerful, quiet and cheaper to maintain. And owners quickly adapt to the new charging routine once they take the car home — Dovorany says most people end up really appreciating that they can charge at home and never visit a gas station.
"But it's super hard to convince people before they've owned an [electric vehicle] how much they're going to like that," he says. "And so we can't really sell it per se."