Bah, all this focus on battery tech. All we need to do is make a device that will efficiently transmit power to the vehicle wirelessly. No need for heavy batteries, and can run as long as you want. Think outside the box people!
Well, technically you can.... I've done it myself.
“The modern astrophysical concept that ascribes the sun’s energy to thermonuclear reactions deep in the solar interior is contradicted by nearly every observable aspect of the sun.” —Ralph E. Juergens