Tesla had something planned like that at one point I remember. I guess they dropped those plans.The benefit would be if EV makers made it such that batteries were hot swappable, since waiting 30+ minutes for rapid charging or 4+ hours for "fast" charging seems to be one of the larger roadblocks for EV adoption, or at least one of the largest complaints people who don't have an EV (and probably never will) tends to bring up.