On April 10, 1994, about 1045 eastern daylight time, a Cessna 310J, N310JF, registered to Richard L. Cloninger dba Le Aire, experienced collapse of the left main landing gear on landing at the Ocala Municipal Airport, Ocala, Florida, while on a 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The airplane was substantially damaged and the commercial-rated pilot and three passengers were not injured. The flight originated from the Gastonia Municipal Airport, Gastonia, North Carolina about 0830. The pilot stated that he failed to turn on the generators as required by the checklist and about 1 hour into the flight, he discovered that battery power supply had been depleted. The flight continued to the destination and he lowered the landing gear manually. Without electrical system power the landing gear down and locked light did not illuminate. After touchdown, the left main landing gear collapsed and the airplane veered off the runway into grass. The airplane was placed on jacks and using the airplane's electrical system, the landing gear operationally tested normally using the landing gear motor.