What happened
During a flight to Oxnard, the pilot performed a long cruise descent using very low power output. The pilot was unaware that the aircraft's electrical system utilized generators rather than alternators, and the engine speed maintained during the descent was insufficient to keep the battery charged.
Upon landing, the pilot shut down both engines and deplaned the passenger. When attempting to restart the engines, the pilot discovered the battery charge was too low for a successful start. The pilot set the brakes and successfully started the right engine via hand-propping. Returning to the cockpit, the pilot attempted to use the right engine generator to assist in starting the left engine, but the engine would not crank sufficiently to achieve a start.
The pilot then retarded the right engine throttle to idle, ensured the brakes were set, and exited the aircraft to hand-prop the left engine. The left engine started but immediately transitioned to a high power setting. Before the pilot could re-enter the cockpit, the aircraft moved from its parking space and began traveling in circles. During the third circle, the left wing struck a fence and a tree.
No injuries were reported.