Most people eat 3 meals a day so a charge only has to last about 4 hours of driving. And anyone willing to pay for and carry an extra battery is better off having it plugged in, which simply makes the car a more expensive, longer range EV, and there are plenty of those already.
What problem are you trying to solve?
Longer distances on a charge?
Most people eat 3 meals a day so a charge only has to last about 4 hours of driving. And anyone willing to pay for and carry an extra battery is better off having it plugged in, which simply makes the car a more expensive, longer range EV, and there are plenty of those already.