Re: In other words...
Battery tech isn't standing still. But it's also not advancing especially quickly. LOTS of money has been is and will continue to be spent on battery R&D. Will batteries be better in two decades? Yes. Are your expectations realistic? Probably not very.
Recommended reading: Tom Murphy's articles at https://dothemath.ucsd.edu/ Murphy is a physicist at UC San Diego who for many years has driven electric vehicles and run his household largely on solar power. But he does that largely by living in a very mild climate where heating and cooling needs are minimal and by consuming far less energy than most of us in other areas as well. His opinions are worth taking into account. He is not all that optimistic about the non-fossil fuel future.
Biting the hand that feeds IT
