Shai Agassi stood in a warehouse on the outskirts of Tel Aviv one afternoon last month and watched his battery-swapping robot go to work. He was conducting a demonstration of the curious machine that is central to his two-year-old clean-energy company, which is called Better Place. Agassi�s grand plan is to kick-start the global adoption of electric cars by minimizing one of the biggest frustrations with the technology: the need for slow and frequent recharges. The robot is the key to his solution. Unlike most electric-car technologies, which generally require you to plug your car into a power source and recharge an onboard battery for hours, the Better Place robot is designed to reach under the chassis of an electric car, pluck its battery out and replace it with a new one, much the same way you�d put new batteries in a child�s toy.