A C172 EXPERIENCED AN ELECTRICAL SYS ANOMALY WITH VARIOUS SYS FAILURES CAUSING THE PLT TO DECLARE AN EMER AND DIVERT.

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I WAS ON AN ANGEL FLT MISSION FROM ZZZ1 TO ZZZ2. I HAD ACTIVATED A VFR FLT PLAN AND WAS ON FLT FOLLOWING WITH CTR. ABOUT 5 MI W OF ZZZ2 INTXN; I NOTICED THE FAILURE INDICATOR LAMP FOR MY LASAR ELECTRONIC IGNITION SYS CAME ON. I CHKED ITS CIRCUIT BREAKER AND IT WAS OK. THE PLANE CONTINUED FLT ON ITS 2 MAGNETOS BACK-UP SYS. I THEN NOTED A FLICKERING OF THE FREQ INDICATORS FOR THE KING 155 NAV/COM SYS. CIRCUIT BREAKERS CHKED OUT OK. I CALLED THE CTR CTLR AND ADVISED I WAS HAVING ELECTRICAL PROBS; INTERMITTENT RADIO FAILURES AND THAT I WAS DIVERTING FOR LNDG AT ZZZ AND ASKED THE CTLR TO ADVISE ZZZ APCH. THE CTLR THEN ASKED FOR MY ALT. I REPLIED AND ADVISED I WOULD IDENT THE XPONDER. HE AGAIN ASKED MY ALT AND SAID HE WAS NOT GETTING MY XPONDER. I AGAIN RESPONDED WITH MY ALT AND AGAIN ASKED FOR MY STATUS TO BE RELAYED TO ZZZ. I THEN NOTICED THE GARMIN GPS 155XL WAS NOT RESPONDING TO INPUT COMMANDS. I THEN SHUT DOWN ALL NON-ESSENTIAL ELECTRICAL CONSUMERS; BUT LEFT 1 RADIO ON AND THE NAV LIGHTS AND STROBE LIGHTS. I ATTEMPTED TO RECONTACT CENTER TO DECLARE AN EMER; BUT I DON'T KNOW IF THEY HEARD ME. I HAD ZZZ IN SIGHT AND KNEW THE LOCATION OF BOTH ZZZ AND ZZZ3. I COULD NOT CONTACT APCH DUE TO MY RADIO FAILURE BUT ELECTED TO ENTER THE CLASS C AIRSPACE ANYWAY; HOPING THEY WOULD BE AWARE OF MY STATUS. I CONSIDERED LNDG AT ZZZ3 (OUTSIDE CLASS C AIRSPACE) BUT ELECTED NOT TO ATTEMPT A LNDG THERE AS THE LIGHTING IS PCL AND WITHOUT RADIOS I COULD NOT BE ASSURED I WOULD BE ABLE TO LAND SAFELY. THE RADIOS CAME BACK ON WHEN I WAS 4-5 MI FROM LNDG. I CONTACTED ZZZ TWR AND ADVISED MY INTENTIONS. TWR RESPONDED THEY KNEW I WAS INBOUND AND THAT I WAS CLRED TO LAND. THEY ASKED IF I NEEDED FURTHER HELP UPON LNDG. I ADVISED THAT IT DID NOT SEEM LIKELY. I LANDED SAFELY AND TURNED OFF ON TXWY. UNABLE TO CONTACT GND I BEGAN TO TAXI TO NEARBY PARKING AT AN FBO; WHEN THE RADIO CAME ON ONCE MORE AND I WAS ABLE TO REACH GND WHO CLRED ME TO PARKING AND INSTRUCTED ME TO CONTACT THE TRACON SUPVR BY PHONE UPON DEPLANING. I SPOKE WITH THE SUPVR AND ADVISED HIM OF THIS SEQUENCE AND OF MY DECISION TO PENETRATE CLASS C AIRSPACE WITHOUT RADIO CONTACT AS A FLT SAFETY DECISION. WE DISCUSSED LNDG AT ZZZ3 OR ZZZ4 OR ZZZ5 ARPTS. HE CONFIRMED THAT CTR HAD CONTACTED THEM AND THAT TRACON HAD ME ON PRIMARY RADAR AND HAD DIVERTED OTHER TFC TO ALLOW ME TO APCH BY MY OWN NAV. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT THE VOLTAGE REGULATOR WAS EITHER INTERMITTENT OR HAD FAILED. BECAUSE HE WAS POWERING DOWN ACFT EQUIP IN ORDER TO CONSERVE BATTERY PWR; HE DID NOT KNOW IF THE REGULATOR FAILED COMPLETELY OR WAS MALFUNCTIONING AND PARTIALLY CHARGING THE BATTERY.