Tesla CEO Elon Musk this week revealed details about the car company’s plans to offer a battery swapping service, which the company originally unveiled last year. Invited Model S owners will have the opportunity to participate in the new pilot program by appointment-only in Harris Ranch, CA. The immediate goal is to test the technology and “assess demand;” if all goes well, Tesla could roll out the service even further to areas close to its growing Supercharger Network.

The battery swapping service promises to swap out a Model S battery pack with a fully-charged one in 90 seconds, which is less time than it takes to fill up a full tank of gas. Tesla demonstrated how it would work on stage last summer, but there hasn’t been a peep from the company since. Now the automaker is ready to begin “exploratory work” on the battery swap technology.

At least initially, battery swap will be available by appointment and will cost slightly less than a full tank of gasoline for a premium sedan. More time is needed to remove the titanium and hardened aluminum ballistic plates that now shield the battery pack, so the swap process takes approximately three minutes.

If enough Tesla owners express interest in the program, the company will consider putting in the resources for battery swap stations. If Tesla can indeed get the time down to 90 seconds or less, owners will be able to stop at a facility and be back on the road with a fresh battery in no time. It certainly beats the time it takes to charge a Model S battery—or fill up a tank of gas.