The pilot stated that while at 8,000 feet he began losing electrical power to all of his instruments, including radios. He had the airport in sight, so he did not declare an emergency, but did switch his transponder to 7600. He stated that he selected the landing gear handle to the down position, he did not remember acknowledging the gear position indicator, nor did he remember hearing the gear motor, and he did not use the hand crank for the landing gear. He said he was unable to lower the flaps. On final, he pulled the power, but the engine stayed at full power despite the fact that the throttle was retarded. He landed fast. He tried to flare but the airplane was going too fast. He said he landed bounced, and then the airplane came back down hard. The pilot stated that he was very nervous and distracted by all of the system failures. Examination of the airplane by a Federal Aviation Administration inspector found the battery dead, and substantial damage to the engine compartment and forward cabin/cockpit.