What about this? https://www.tesla.com/videos/battery-swap-event

Or maybe those weren't production cars?

NIO is the only car maker I know of that does battery swapping. Tesla's AFAIK were only a tech demo.

That event was over a decade ago. Those were not production cars, and production at Tesla has moved away from this model and into "structural packs" where the battery pack is major structural component of the frame.

Also, that demo was pretty much there to get some tax subsidies or something. They built the system to comply with the minimum to qualify, and once they got the money they didn't do anything else with it. Those cars weren't really production at all.

I mean, technically you could swap out the entire cab every time it needed to be charged. The goal is to get the trailer to the destination, not the cab.

There are several problems with that, you end up with a lot more idle equipment than just the battery pack, you've got to either be constantly switching drivers or drivers have to be constantly switching cabs, you need facilities to swap trailers and charge cabs, etc etc etc.

But tractor trailers already have a convenient modularity built in, is all I'm saying.

Tesla-semi-as-pony-express would be interesting, but isn't really compatible with _selling_ the actual truck as a product; no one wants to swap _their_ truck with someone else's, except the guys with above-average wear on their truck.

The same dynamic limits battery swaps.