GM began developing electric vehicle technology back in the 1960s and '70s. This photo includes some of those early prototypes that lead to today's Chevrolet Bolt. On the left is the '66 Electrovair II powered by silver-zinc batteries. The '66 Electrovan was featured an early fuel cell to generate power. The XP-512 was one of a series of small, lead-acid battery powered, urban vehicles. The '77 and 1980 Chevettes were driven by lead-acid and nickel-zinc batteries respectively.