A mobile robot includes a chassis defining at least one chassis volume and first and second sets of right and left driven flippers associated with the chassis. Each flipper has a drive wheel and defines a flipper volume adjacent to the drive wheel. The first set of flippers is disposed between the second set of flippers and the chassis. Motive power elements are distributed among the chassis volume and the flipper volumes. The motive power elements include a battery assembly, a main drive motor assembly, and a load shifting motor assembly.