Back at the dawn of the electric car era, when cars like the Nissan LEAF, BMW i3, and Tesla Model S were just starting to get noticed, a lot of people thought battery swapping instead of battery charging might be the way to go. The logic was sound. If you could swap out a discharged battery and replace it with a fully charged one in a few minutes, that would be better than hanging out at a service area on the interstate for an hour or so, waiting for fresh electrons to insinuate themselves into your battery pack, wouldn’t it?

Tesla battery swapping system

Tesla explored battery swapping briefly, then decided it did not make economic sense and dropped the whole idea after building one facility in Silicon Valley. Now, the idea is back. A patent application dated September 14 describes a system that would raise a vehicle in the air with one set of hydraulic lifts while another inboard lift would drop the battery pack and replace it with a fully charged unit. Here is what the patent abstract says:

A system for exchanging an electrical energy storage system (EESS) of an electric vehicle includes. An EESS station is configured to position an electric vehicle in x and y directions. A vehicle lift raises the electric vehicle to a predetermined height. An EESS lift supports and lowers the EESS and replaces the EESS with a differing EESS. The vehicle lift may be an inboard lift and the EESS lift may be an outboard lift. The system may also include one or more rollers configured to guide the electric vehicle. The system may include a horizontal door having at least one tube positioned thereon for guiding the electric vehicle and/or at least one vehicle chock for positioning the electric vehicle in at least one of the x and y directions. The vehicle lift may include lifting arms to engage jack pads of the electric vehicle.

Such systems could be installed at service stations or even incorporated into a mobile rig. While the patent speaks about using the battery swapping system for  Model S and Model X vehicles, Elon Musk is on record as saying that if Tesla decided to pursue the idea, it would apply to commercial vehicles as well, according to  TechCrunch.

Gee, Tesla doesn’t make any commercial vehicles does it? Oh wait. It’s going to take the wraps off the Tesla Semi on October 26, isn’t it? Hmmm, could there be a connection?