As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BATTERY CHARGE ANNUNCIATOR ILLUMINATED FROM AFTER START TO AFTER TAKEOFF, WHEN CHARGE RATE DECREASED BELOW 7A, MASTER CAUTION FLASHERS W/N REMAIN EXTINGUISHED-TRIPPED MULTIPLE TIMES. MAINTENANCE WAS UNABLE TO DUPLICATE THE DISCREPANCY DURING TROUBLESHOOTING ON GROUND.