ACFT EQUIP PROB. VOLTAGE REGULATOR WAS INOP AND THE BACKUP REGULATOR WOULDN'T COME ON THE LINE. BEING WITHOUT ELECTRICAL PWR OTHER THAN BATTERY; RPTR PLT HAD ONLY BACKUP ATTITUDE INDICATOR AND WAS IN IMC; SO RPTR CLBED TO GET OUT OF THE IMC WITHOUT CLRNC FROM ATC. AFTER RECYCLING THE VOLTAGE REGULATOR THE PWR WAS RESTORED.

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VOLTAGE REGULATOR WAS LOST. SWITCHED TO #2 VOLTAGE REGULATOR AND NOTHING HAPPENED. BATTERY PWR WAS ALMOST LOST. ATTITUDE INDICATOR IS ELECTRIC SO THAT ROLLED. I CLBED TO SEE IF I COULD GET OUT OF THE CLOUDS TO AN ALT OF APPROX 7000 FT MSL. I THEN TOLD THE CTLR OF MY INTENTIONS WITH A WEAK RADIO. I HAD A VACUUM DRIVEN ATTITUDE INDICATOR ON THE COPLT'S SIDE BY THE BOTTOM OF THE PANEL. I USED THAT TO KEEP WINGS LEVEL UNTIL I STARTED BACK TO MY ORIGINAL ARPT. AT THAT TIME I RECYCLED THE VOLTAGE REGULATORS AND MY PWR WAS RESTORED. I LANDED BACK AT AVP SAFELY. I FEEL THAT IF I DID NOT LET THE BATTERY GO BELOW 17 VOLTS; I WOULD HAVE HAD ENOUGH CURRENT TO EXCITE THE ALTERNATORS TO WORK ON THE SECOND VOLTAGE REGULATOR. I FEEL THAT THIS IS WHY IT TOOK TIME FOR THE SECOND REGULATOR TO COME ON LINE. I CLBED TO 7000 FT MSL BECAUSE I WAS IN TERRAIN WITH HILLS (APPROX 3000 FT MSL). BEING IN IMC AND NOT HAVING AN ATTITUDE INDICATOR MOMENTARILY WAS MY JUDGEMENT TO MAKE THE CLB WITHOUT IMMEDIATE CLRNC. WHEN PWR WAS RESTORED THE ATC CTLR CLRED ME TO 7000 FT MSL.