Tesla is still exploring options to make swapping vehicle battery packs easier and faster. This patent filed in May reveals one option that would allow technicians to change out packs in less than 15 minutes.

This isn’t the first of such ideas. Back in 2014 Tesla briefly played with an automated system that swapped Model S battery packs in less than 90 seconds. That idea seemed to be shelved as the Supercharger network started rolling out.

The system described in this patent could be installed in a service station or integrated into a mobile rig. A Model S or X would either drive onto ramps or a lift where technicians would then assist the machine in swapping the packs.

The patent notes that this is for Model S and Model X vehicles though it could have broader applications. Elon Musk previously said if Tesla pursued a mobile battery swapping program, it would be to support commercial vehicles — just like the semi-truck platform Tesla is about to unveil.