On June 24, 2000, at 1101 eastern daylight time, a Piper PA-30, N8629Y, was substantially damaged when the gear collapsed during landing on runway 09 at Key West International Airport in Key West, Florida. The private pilot and one passenger were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight being conducted under Title 14 CFR Part 91. The flight originated from St. Lucie County International Airport, Fort Pierce, Florida, at 0945. According to the pilot, he originally departed Bowling Green, Ohio, en route to Macon, Georgia, in order to have the airplane's autopilot system inspected. No discrepancies were found and the flight continued on to Fort Pierce, Florida. While approaching Cape Canaveral, Florida, the airplane experienced an electrical system failure. The pilot elected to divert to Space Coast Regional Airport in Titusville, Florida. According to the pilot, "with the help" of the passenger, the landing gear was manually lowered in the down and locked position and an uneventful landing was made. The following morning, a maintenance technician charged the battery and no additional discrepancies were found. While taxing to the active runway, once again the entire electrical system failed. According to a maintenance technician, the battery was again found to be the problem and a new one was installed. Prior to departure, the second passenger who assisted the pilot in manually lower the landing gear elected to return to Ohio by car, leaving the pilot and his wife to continue on to Key West, Florida. The flight was then conducted without incident from Titusville, Florida, to Fort Pierce, Florida. Upon landing at Fort Pierce, a maintenance technician at the airport replaced the right alternator and a broken wire from the left alternator. The flight then continued on to Key West, Florida. According to the pilot, the airplane experienced another complete electrical system failure 14 miles north of Key West. The pilot attempted to manually lower the landing gear, but was unable to get it in the down and locked position. The pilot reported that he "attempted to manually lower the landing gear; however, it would not lock into place." According to an interview conducted by an FAA inspector two days following the accident, the pilot stated that he "did not have the muscle to manually get the landing gear completely down and locked." Upon touching down on runway 9 at Key West, the landing gear collapsed.