Electric cars:

Back when i was a bit younger and played with toy trucks and all a lot . I remember getting the cheap rechargeable batteries . Wait all day. For a mere 10 maybe 25 minutes to drive a RC truck. The battery life is pretty ridiculous  for something that couldn't weigh 5 maybe 10 lbs .  Fast forward to today. Your seeing electric cars that you can ride in have well over 100 miles of range with added benefits of being extremely quick.  Now days these batteries are nothing like the ones you used to buy at dollar general . These are made from newer materials . Lithium batteries they are lighter and more energy dense than the old school batteries. I built an electric bike with 4 36 volt 4.4 ah batteries they all sit nicely between the handle bars and the seat . Rewind back 20 years ago . You would need a trailer for that kind of power. So as electric cars evolve . They will benefit from more energy efficient motors obviously and these motors even though are efficient they are power hungry so if they are going to be self contained . Battery tech will become more evolved as time goes on. 20 years from now there may be some type battery that is so energy dense that it can hold several kw of energy in your hand no one knows the future for certain one thing for sure as of now batteries are not going to go away. Almost everything can be ran on a battery. Whole homes are now powered by nothing but a battery.  Will be interesting to see what turns battery tech takes in the next 10 years.