A. and B. are easily handled. First, there is no problem with current electric vehicles. They stay just like they are. I am talking future here not the past. Second, it doesn't matter what the battery weighs. There is such a thing as hydraulics! You wouldn't physically lift the battery and put it in your car regardless of size. The swapping would be automated. But we can't achieve these huge advantages and consumer savings without mandating certain aspects of new electric vehicle design. I love the idea of flying cars, and i intend to get one as soon as they are guaranteed not to fall out of the sky and not to crash into other flying cars in heavy, rush hour traffic.
EV battery swaps are available now, but not in your neighborhood. https://www.nio.com/news/10-Billion-Kilometers You're not ready for flying cars yet. Until then, you could try frying cars ...
Hey guys, NIO does exactly what you describe, but in China. Drive your EV to a battery swapping station and within minutes you're out with a fully charged battery. Apparently there are logistical complexities with such a solution, ensuring enough charged batteries are stocked and then charging those left at the shop. It's complicated enough that NIO is having a difficult time not losing money doing it. Another company, GOGORO, does the same but this time in Taiwan, for electric mopeds. There they are successful, with racks of swappable batteries on designated sidewalks. Direct card payment, pull the battery off the rack, swap with the old, and off you go. The advantage is they are a leading manufacturer of mopeds in Taiwan, but they also signed deals with other manufacturers to make mopeds to accept Gogoro's battery system. They are testing their solution in Singapore, Philippines and India.
I would think ensuring enough batteries are on hand shouldn't be much of a problem at all. But making money is a different issue entirely. Competition will decide how much profit can be made. If the batteries being rented out aren't very reliable or too expensive to manufacture compared to the competition, there will be insufficient profit margin. The problem of stocking enough charged batteries should be less than the problem of a gas station keeping enough gasoline on hand, i.e., not a problem at all under normal circumstances.. That's because swap stations continually refresh their stock of batteries by charging the discharged batteries swapped out for charged ones. All they need is a small buffer stock of standard batteries in standard sizes. Then when you pull in for a swap, the station will pull your battery and read how much charge remains. You'll pay for the difference between the charge on the battery your getting and the one removed. And you pay an additional small up-charge for use of the battery which provides for amortization of its initial cost. The swap stations create their own stock of charged batteries mainly out of discharged batteries. Another feature of battery swapping that is very appealing from the consumer's viewpoint is that the consumer won't be locked into obsolescent battery technology the way they would be if they owned the battery they use. Competition will determine which battery technologies are most cost effective! It's a very capitalist approach to supplying batteries for EVs that should result in very high tech, efficient batteries being developed.