The bigger risk is you need a standard battery pack. Sure you can put 3 in a truck or something, but you lose all the space that a standard battery size wouldn't fit but you can cram a cell in. Electric car design is about stuffing batteries where there is space - you need a lot of cells, but the individual cells are small.

> of unknown provenance

I don't understand the comment. Of course they know where the batteries come from. They know everything about the battery.

As long as you can always swap your battery again I don't see the problem

As long as the average battery health in the system is like 90% and the minimum is say 80% why would you care if you're getting a new battery every few days?

If anything it removes a big cause of depreciation from your car

Eh?

In some mysterious future where swapping EV batteries during a road trip is a normal activity, then the battery packs won't be living in a vacuum -- their status can be known. Whether it is known by reading the pack's own electronics, by status reports from connected vehicles and charging stations, by direct measurement, or by some combination of these things: The status is knowable. It doesn't have to be a big ball of mystery.

How much value the marketplace finds in this health status is a different question. And this question is one that we cannot yet know the answer to -- this is not a reality that we presently live in.

We can speculate about how that potential future may be shaped, but that kind of speculation is kind of meritless since that version of the future may never actually happen (and at the present, it sure does seem very unlikely to happen any time soon).