Rivian is making more modular options available with the electric line. A recent patent shows the startup carmaker filing for a removable, auxiliary battery pack and the associated technology.

The patent filing was first discovered on the Rivian forums. It was originally filed last July and remains pending in the United States Patent Office. It details a system that would allow drivers to attach an additional battery to their vehicle, extending their maximum range.

Most of the "top of the line" models that Rivian offers boast an approximate 400-mile range. It remains unsaid what capacity an external battery would have. And ergo, what it would extend the range by. The patent diagrams show a pickup as the example vehicle. So it's quite possible that the external option would only be available for that classification. You could easily place a battery in the truck bed, but where would you fit one in an SUV?

Rivian has some heavy cash on hand, thanks to a recent investment by Amazon. I could imagine that the online shopping company would create a system of charging external batteries at their warehouses and swapping them out on the fly. This way, their electric delivery trucks would (in theory) never have to sit and wait for a charge.