Abstract: A hybrid-powered slow-speed vehicle (400) fundamentally comprising battery-electric slow-speed (BESS) vehicle (107) plus auxiliary-drive ICE-powertrain (200), hub-coaxial wheel positioner (269) and auxiliary-drive operational controller assembly (300); powertrain (200) having [a] high energy-density fuel supply (203), sufficient auxiliary driveline operational space (283) urged by wheel-positioner (269), [c] auxiliary-power driveline (235), component couplings of the driveline (235) ending with operable attachment of distal powerwheel (256) to auxiliary-driveline rear traction-wheel (262); operational controller assembly (300) within vehicle-driver zone (110); hybridized BESS-vehicle (400) extending travel range (145) of original BESS-vehicle (107), utilizing primary electric powertrain (151) and auxiliary ICE-powertrain (200) in various cooperative sequences and combinations of operations, retaining many advantages of original vehicle (107), while adding others, especially notably the opportunities to extend