Re: Full charge in 10 minutes?
A limited-distance spare battery wouldn't help me much, either. When I'm doing local errands, a regular EV would probably work fine (though you need decent ground clearance for our private road and many others in the area, and in the winter AWD is often helpful, if not usually strictly necessary, so those limit my choices).
But I routinely make a trip that's 640 miles / 1025 km each way, much of it through essentially uninhabited areas. It will be a long time before charging stations are available on that route, and I'm not keen to add 90 minutes or more to my travel time, so charging (or battery swap) would have to be fast.
Also, my vehicles aren't garaged, so those packs would have to withstand large daily temperature swings, with highs well above 100° F / 40° C (in the battery compartment, sitting inside the vehicle that's sitting in the sun) and lows below 0° F / -20° C (not on the same day, of course, but those are the seasonal extremes).
I'm glad to see continuing improvement in battery technologies, and some day I expect we'll be using photovoltaic plus one of these home battery packs for a bunch of our domestic use. But EVs don't look like they'll be practical for me for a long time yet.
And in any case I don't ever want another new car. New cars are horrible these days, with their ghastly touchscreens and built-in spyware and the rest. It's used from here on out.