The pilot reported that he had shutdown the engine on a remote dirt airport to inspect the tires before takeoff. When he attempted to restart the engine the battery was insufficiently charged, and would not start the engine. The pilot decided to attempt to start the engine by hand propping it. He set the throttle, the brake, and turned the magnetos to on. The pilot used a hand-prop method to attempt to start the engine. The engine ultimately started but before the pilot could enter the airplane, it accelerated and went on an excursion first hitting a berm and then continuing over a cliff. The airplane sustained substantial damage to the wings and fuselage.