C310 PLT HAS RADIO FAILURE DURING APCH TO DAL.

Narrative

PRIOR TO PENETRATING THE DFW CLASS B AIRSPACE; I BEGAN EXPERIENCING PROBS WITH MY XPONDER. ATC ADVISED ME OF THE PROB AND ORDERED ME TO RESET MY XPONDER. WE WERE UNABLE TO MAKE IT XMIT BUT WERE ALLOWED TO ENTER CLASS B AIRSPACE. WITH FREQUENT ALT AND POS VERIFICATION; I WAS ALLOWED TO PROCEED TO DAL. AFTER ARRIVING OVER LOVE FIELD; I ENTERED A R DOWNWIND FOR RWY 13R AND ATTEMPTED TO SET APCH FLAPS 15 DEGS). WHEN I HIT THE FLAP SWITCH; I NOTICED A DROP IN PWR TO THE ACFT FLT INST LIGHTS AND THE FLAPS FAILED TO DEPLOY. AT THIS POINT; I KNEW THAT ALL PWR WAS COMING FROM A BATTERY WHICH WAS LOW ON PWR. THIS LOW SUPPLY OF ELECTRICITY ALSO RENDERED THE LNDG GEAR MOTOR USELESS. ONCE I INFORMED TWR OF MY PROB AND EXPLAINED THAT I WOULD NEED TO CRANK THE GEAR DOWN; THEY GAVE ME A HDG TO FLY AND A RADIO FREQ CHANGE FOR VECTORS TO LNDG. AFTER CHANGING FREQS; I WAS NO LONGER ABLE TO MAINTAIN RADIO CONTACT. SHORTLY THEREAFTER; I LOST ALL ELECTRIC PWR. UNABLE TO SEE DAL BEHIND MY ACFT; I MAINTAINED MY LAST GIVEN HDG UNTIL I SPOTTED DTO; AT WHICH TIME I MADE A SAFE LNDG. THE CAUSE OF THE ELECTRICAL PROB HAS YET TO BE DETERMINED; BUT DUAL GENERATOR OR REGULATOR FAILURE IS SUSPECTED.