"32 Hours Needed To Charge a Tesla Roadster Using Common Electrical Outlet" Green Car Advisor

32 Hours Needed To Charge a Tesla Roadster Using Common Electrical Outlet

By Scott Doggett, Contributor

A Connecticut newspaper reported Saturday that it "could take up to 32 hours" to charge a Tesla Roadster using a standard 110-volt outlet.

The news has since taken the blogosphere by storm, but according to Darryl Siry, Telsa Motors' vice president of marketing, it shouldn't have.

In a conversation with Green Car Advisor today, Siry not only confirmed the report in Greenwich Time, but said the amount of time needed to charge a Roadster's lithium-ion battery pack using the same outlet you might plug a toaster into would actually exceed 32 hours.

Here's the deal. The all-electric Roadster is fitted with a 53-kilowatt-hour battery pack. To figure out how long it would take to charge it, you multiply volts by amps and divide 53,000 by that sum.

To get the number of hours required to charge a Roadster battery pack using a standard 15-amp 110-volt outlet, you multiply 15 by 110, which gives you 1,650. Next, divide 53,000 by 1,650 and you've got the number of hours needed to charge the battery pack: 32.12.

It's for this reason, Siry said, that the very first thing you do after buying a zero-emissions Roadster is hire an electrician to install a 70-amp 220-volt outlet in your garage.

Most American homes have a 200-amp 220-volt circuit going into them. Typically, 30 of those amps are used to power an oven or a clothes dryer.

The electrician would run a 70-amp 220-volt conduit from the breaker box (or electrical panel, if you prefer) to the garage and hook the conduit up to a new 220-volt outlet. It's an easy job, one that shouldn't take a pro more than a couple of hours to do.

To figure out how long it would take to charge the Roadster's battery pack using the new outlet, multiply 70 by 220, which gives you 15,400. Divide 53,000 by 15,400 and you've got your number: 3.4 hours.

Or just enough time to thoroughly detail the car before hitting the road again.