Nearly a month after announcing plans to set up a high-speed network of “Supercharger” stations across the U.S. and Canada, Tesla CEO Elon Musk is hinting the start-up electric vehicle maker might also adopt a battery swap system that could allow owners of the new Model S sedan to switch in a freshly charged battery pack “faster than you could fill a gas tank.”

Tesla has been exploring the idea of swapping batteries for years. Conceptually, the approach is simple. When one battery pack runs down, simply switch it out for another, much like changing batteries in a flashlight.