As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, HAD BRIEF BATTERY CHARGE ANNUNCIATOR ILLUMINATION. THEN, AFTER NEXT TAKEOFF ANNUNCIATOR REMAINED ILLUMINATED AND WAS ACCOMPANIED BY BATTERY AMMETER AND BOTH GENERATOR LOAD METERS CYCLING. AMMETER CYCLED FROM 0 TO 30A AND LOAD METERS CYCLED FROM 20 TO 35 PERCENT UNTIL BATTERY MASTERSWITCH WAS TURNED OFF. PROCEEDED TO NEXT LANDING AND MAINTENANCE CLEANED BATTERY AMMETER SHUNT, BATTERY TERMINALS, REPLACED BATTERY AND PERFORMED EXTENSIVE OPERATIONAL CHECK BEFORE CLEARING DISCREPANCY.