Koei Saga, senior managing officer in charge of drivetrain R&D at Toyota, has informed Automotive News that Toyota is now thinking of making the Prius in the U.S. by 2015 and wants to get hybrid drivetrain components – motors, inverters, batteries (likely lithium-ion packs) – from North American suppliers. The base fourth-gen Prius will probably still use nickel-metal hydride batteries, but the batteries made in the U.S. might be li-ion.
A 2015 timetable means it is likely that America would make the fourth-gen Prius model, which is due around that time. The reason this story keeps coming back is because it makes sense to build the Prius in the States. Sales are strong here and expected to grow, so extra production somewhere will almost certainly be needed to meet demand. Plus, a strong yen means that Prius vehicles built in America would likely come at a lower cost to Toyota.
Toyota currently makes the Camry hybrid in the U.S. at its plant in Georgetown, KY. The question as to whether the U.S. Prius would be made there, at Toyota's Mississippi plant, at the Tesla plant in Fremont, CA (formerly known as NUMMI) – where rumors about Toyota and the electric car automaker building electric cars like the RAV4 EV have also floated around in the past – or somewhere else completely will need to be answered at another time.