That's what we call it at work. I work with heavy duty zero-emission vehicles. I don't where it came from, but I first heard it in the 1990s from guys who designed motor drives. Transportation is a traction application and the motor drives (inverters) are configured for traction as opposed to say, servo operation. So I think it was natural to call the energy source a traction battery, especially to distinguish it from the low voltage battery. I am not up to speed on Tesla terminology or light duty vehicles in general, but I'm catching up.Just curious. I've never heard it called a traction battery. Where does that term originate from?