By now, you’ve certainly heard of electric cars. Maybe you’re even thinking about buying one. And if you’re like most people, you may have some questions about the new technology. How do you charge an electric car? Do you need special equipment or do you just plug it into an outlet in the garage? Is your house able to supply enough power for charging an electric vehicle or will you need to get it rewired? Take heart – you’re not the only one asking these questions. Recent surveys indicate that a large number of Americans don’t have a lot of information about electric cars. One study showed that only about one in five respondents said they are “very familiar” with alternative automobile technologies.

Another consideration is cost, specifically the cost involved in recharging an electric car in your garage. Depending on which car you buy and the age of your home, the cost of getting the garage prepared for charging an electric car can range from nothing to a few thousand dollars. Since older homes weren’t constructed with electric cars in mind, and many older homes can’t supply enough power to charge them, you may have to rewire the garage. It takes at least a 12-amp circuit to charge an electric vehicle in a timely manner. According to the therobsway.com blog, the circuit should only be used for charging the car, as any other electric device that draws power from the circuit will increase the charging time.

But depending on which one you buy, a dedicated circuit may not be adequate for charging an electric vehicle. Most garages were built with 120-volt outlets. A 240-volt outlet, (like the ones used for large appliances like washers) with nothing else drawing power from it can speed charging time by about half. The Nissan Leaf takes about eight hours to charge on a 240-volt circuit. That time increases to about 16 hours on a 120-volt circuit. The Chevrolet Volt needs about 5 hours to charge on a 240-volt circuit, and about 10 hours on a 120-volt circuit.

According to GM, recharging the Volt won’t add more than about an additional $1.50 per day to your electric bill, based on the national average electricity cost of 11 cents per kilowatt hour. AeroVironment, the company that manufactures Nissan charging stations, recommends installing a special 240-volt station in your garage. There’s a basic station that starts charging your car when you plug it in and a smart station that automatically charges the car at night, when the load on the power grid is lower. Whichever you choose, you’ll need a qualified electrician with experience in electric vehicle technology in order to know what you’ll need and to install the 240-volt station to a dedicated 40-amp circuit. “This is no different than installing an appliance or something else,” said Kristen Helsel, vice president of electric vehicle solutions for AeroVironment. “We need to take the power from your breaker box and run it to where you want the charging station installed.”

“Most cars are parked more than 10 hours,” said Britta Gross, GM’s director of electrical infrastructure. “If I were a consumer, I would always try 120 first, and if you’re not satisfied, then you can consider the 240-volt upgrade.” GM’s Volt charging unit runs about $500 and costs about $1,500 to install. If additional work is needed in the home it could cost even more. But if you don’t drive very far, you may not need a special charging station. A 120-volt outlet will work fine if you only drive 20 miles a day because you won’t have to charge the battery completely every night.