Comment Re: Let's eat Grandma, shoots, and leaves. (Score 1) 167
That makes no sense - we don't know the capacity of the fast-charge battery, and we don't know the charge time of the long-range battery. And the cost of the battery pack is a huge part of most EV pricing, putting two full-capacity but different battery technologies in one car would adds thousands and thousands to the sales price and would push vehicle weight to new, unbelievable, heights.
Putting two batteries in an EV makes as much sense as putting both a diesel and a gasoline engine in a vehicle, because 'one's good for long-haul driving', the other runs on cheaper gasoline and better for 'start-stop' driving in, say, a city-setting.
You've made it make no sense by making specifically the worst assumptions possible. Two batteries. One long haul and one fast charge but sized based on a reasonable usage pattern. Why would anyone mean two full capacity batteries? When the fast charge is topped off, it will run the vehicle while slow charging the long distance battery. Once that is full again, it switches to running off the long distance battery unless you plan on making another stop in a certain amount of time. That way, you can take the largest fast charge possible if you need to pay the higher price to reach your destination or you can switch batteries if you will be able to slow charge later.