Buying an EV? Here's How to Prepare Your Home to Charge an Electric Car

With more cars come more questions. Chief among them: how the recharging routine can work at home.  

“The real opportunity, but also the real difficulty with EVs, is it’s much more like charging a cellphone than going to the gas station,” says Jacob Bolin, electric-transportation specialist at nonprofit consulting firm Advanced Energy. Where possible, he says, consumers want to plug in where they live and work. That could mean having to update their home wiring plus bumped-up electric bills when electricity prices are already trending higher. 

Here, EV charging experts answer common questions about making the switch. 

Can my house handle charging an EV? 

You won’t blow a fuse if you plug your electric car into a standard wall outlet, says Tom Moloughney, senior editor of InsideEVs and host of the “State of Charge” YouTube series.

You also won’t get very far. Relying on 120-volt household outlets, known as Level 1 charging, will give you between 3 and 5 miles of range per hour, Mr. Moloughney says. 

What’s the difference between Level 1 and Level 2 charging?

To reach charging rates between 15 and 40 miles of range per hour, called Level 2 charging, you’ll need to upgrade to a more powerful 240-volt outlet.

Chances are you have some of these outlets at home, since appliances such as electric ranges and clothes dryers rely on them too. For a car, you’ll likely need to install an additional 240-volt outlet in your garage or on the side of your house. 

How much will it cost to upgrade to Level 2 by installing a 240-volt outlet? 

Between a few hundred and a few thousand dollars, says Brent Gruber, who directs EV studies at analytics company J.D. Power. “The difference in satisfaction with charging for Level 2 versus Level 1 is so dramatic that the investment in making those upgrades we feel is worth it,” he says. 

Mr. Moloughney, who consults on residential EV setups, says new wiring should only cost a few hundred dollars if your fuse box has the capacity for a roughly 30- to 50-amp dedicated circuit. “Most houses can spare that extra amount of electricity,” he says. In 95% of the roughly 500 housing upgrades he has assessed, it cost less than $1,000 to make the change, he adds.

In older homes, however, the service panel might already be full. Replacing the breaker panel can cost up to $4,000, electricians say. 

How much will my electric bill go up?

It depends on where you live and which time of day you choose to charge. The national average for electricity is about 14 cents per kilowatt-hour, according to U.S. Energy Information Administration data from November. That means if you drive a Tesla Model Y, which needs about 75 kilowatt-hours to charge completely (the car’s range is about 318 miles with a full charge), a “tank” of electricity will cost you about $10.50.

The national average for a gallon of gas, in comparison, is $3.53 as of Friday, according to AAA. Smaller cars generally hold 12 gallons of gas, so it costs about $42 to fill up. 

If you live in a state such as California with high electricity prices, Mr. Moloughney suggests switching to a time-of-use plan. These plans, which many utility companies offer, adjust pricing based on when you use power. “Your refrigerator has to run all day, but you can set a timer in the car to charge at a certain time,” he says. You can save money setting your car to charge between midnight and 6 a.m., when prices might be 15 cents per kilowatt-hour versus 40 cents at peak times.

Do I need to buy any extra equipment after I upgrade my wall socket? 

Many electric cars come with dual Level 1/Level 2 portable chargers. (You can plug the Level 1 into any standard outlet, and the Level 2 into a 240-volt.) 

Drivers who want to keep the original charger in their trunk as insurance against roadside stranding can buy a high-quality Level 2 charger for between $400 and $700, depending on the features and power level. Mr. Moloughney, who has reviewed dozens of units, likes the Grizzl-E charger as a more-affordable option, and the smart ChargePoint Home Flex Electric Vehicle Charger and Wallbox Pulsar Plus as higher-end choices.  

Can I charge my car outdoors in the driveway? 

Most EV chargers are rated for outdoor use, but certain models hold up better against the elements, Mr. Moloughney says. And you don’t have to worry about getting electrocuted if you charge in the rain. “Twelve years of doing electric-car charging, I’ve never heard of anyone getting hurt from their charger,” he says.  

Still, he advises against plugging in during a lightning storm, which can damage the electronics in your car.

What about superfast chargers? 

You can’t install a DC fast charger at home. The superfast chargers require a level of power (400 to 800 volts) that typically isn’t available in private homes. The chargers also cost many tens of thousands of dollars.

About 16% of EV owners, however, rely primarily on DC fast chargers in places such as grocery stores or office parking lots, J.D. Power’s Mr. Gruber says. 

He adds that home charging isn’t likely holding people back from buying EVs: They are waiting for more-robust public charging. “The people who may not be able to charge at home are likely standing by on the sidelines waiting for better public charging and longer battery ranges to make it easier.”

Write to Rachel Wolfe at rachel.wolfe@wsj.com