Toyota has announced today that it has developed a new plug-in hybrid prototype based on the Prius and has started testing it in Japan with US tests to follow soon after. Toyota’s vice president in charge of powertrain development, Masatami Takimoto, revealed back in May that commercial production of plug-in hybrids is at least several years away but this latest announcement shows that it may not be too far away.

Engineers have increased battery capacity of the new car, which means it’ll be able to travel longer distances on electric power alone than previous prototypes. The vehicle has a cruising range of only 13km on a single charge and its trunk is completely filled with battery packs.

Weighing in at 1,360kg, the plug-in hybrid Prius can travel up 100km/h and takes roughly one and a half hours to charge using a regular household power outlet. Oddly enough, there are several private companies offering plug-in conversion kits for the Prius but Toyota warns any modifications will void warranties and that extra batteries can cause fires.