Unlike the technologies in laptops, smartphones and electric cars, the batteries inside them have been slow to evolve. In Silicon Valley, more than 40 companies are working on finding a battery breakthrough. And they're facing international competition.
After The New York Times published a scathing review of Tesla's Model S electric car, the automaker's CEO took to Twitter to slam the reporter. Disputed facts aside, the timing of the spat could hurt Tesla, which is under pressure to improve its financial performance.
AeroVironment has an unusual combination of products — military drones and electric vehicle chargers. The company's president acknowledges that some workers are uncomfortable with the company's dual interests, but he doesn't see a conflict.