Way back in the summer of 2013, Elon Musk showed off a new piece of tech that could swap the battery of a Tesla Model S in 90 seconds. In one simple move, these battery swap machines made electric cars almost as convenient as their petrol- and diesel-powered brethren. The original plan was to roll out the tech to Supercharger stations in the second half of 2013, but they never emerged. Now, a single Supercharger station in Harris Ranch California has been equipped with the battery swap tech, and Tesla has started inviting some Model S owners to come try it out.