Aside from the fuel cell prime mover, the drivetrain elements of a fuel cell hybrid transit bus are those of a heavy-duty series hybrid vehicle. The U.S. National Fuel Cell Bus Program is advancing all aspects of fuel cell transit bus technology, including fuel cells and other electric drivetrain technologies. Key electric drivetrain technologies developed by General Electric (GE) in the Lightweight Battery-dominant Hybrid Fuel Cell Bus project, their integration to the vehicle design, together with the vehicle build and demonstration plans are described. The GE technologies are sodium metal halide energy batteries, the dual battery energy storage system, energy management controls and dc-dc converter power electronics. Further electric drive vehicle technology developments focused on the fuel cell transit bus application are proposed.