"Twike's battery system was quite unique until Toyota borrowed the basic design for its hybrid electric Prius sedan, which has a single pack with 240 nickel metal hydride (NiMh) batteries.
The Twike is a true hybird using human power to charge batteries. The Twike is a human-electric hybrid vehicle designed to carry two passengers comfortably through any weather with speed and style, and without harmful emissions of any kind. http://twike.us/
Read more here: EV World: The World of Electric, Plug-in Hybrid, Fuel Cell and Alternative Fuel Vehicles