> Given the same electrical interface, dimensions and a compatible BMS, swapping out for a lighter, cheaper battery IS trivial. I don't know about the US, but

> Given the same electrical interface, dimensions and a compatible BMS, swapping out for a lighter, cheaper battery IS trivial. I don't know about the US, but over here in some European countries, there's this thing about vehicle type approval. Changing things like the drive train, brakes, engine or a different type of fuel tank might not be possible because then the vehicle's not conforming to regulation. I could imagine this could be a problem with a changed battery type as well, even if dimensions etc are the same.