The idea of swapping batteries to quickly add range to an electric vehicle isn't new. Rivian thinks it has a better way to add some range, though, and its latest patent application lays the whole idea out in a straightforward manner.
The sleuths at Rivian Forums uncovered a recently published patent application from the fledgling automaker. The patent application is for an "Electric vehicle with modular removable auxiliary battery with integrated cooling." If you couldn't tell from the awfully descriptive name, the application covers a secondary battery that can be added to or removed from a vehicle somewhat easily, yet when plugged in, it acts like any other part of the car.
The idea, shown on a rough sketch of, shows an auxiliary battery module that can be mounted on a specific part of the truck's bed. Not only does the bed have a plug to accept the power from the battery, but it also has cooling hookups that will keep the battery cool using the same cooling system that keeps the primary battery from getting too hot. That means the battery won't have the extra weight of a standalone cooling system, which helps its portability.
Adding a bunch of weight to a new spot on the vehicle might cause the dynamics to change in different ways, but Rivian's system has a plan to counteract that. Once the vehicle has determined that the auxiliary battery is installed, it will make changes to a variety of systems to accommodate the extra mass. It can adjust the suspension firmness, the ride height and even the steering ratio to make the vehicle feel as if nothing's been added whatsoever.
It's possible, of course, that Rivian's idea may never leave paper. Automakers and companies routinely patent innovative technologies in the hopes that competitors won't scoop it up first. That said, range anxiety is still a major roadblock between us and EV ubiquity, so something like this could add some real peace of mind.
Rivian's initial specs for the R1T are impressive, even without that auxiliary battery. Sized a little larger than a Honda Ridgeline midsize pickup, this battery-electric truck packs an estimated range as high as 400 miles (when equipped with its largest optional battery). It's expect to tow about 11,000 pounds and haul up to 1,700 or so. Rivian estimates that the R1T will reach production in 2020, but there's a lot to do between now and then.