As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EXT PWR DROPPED OFF LINE AND MAIN BATT VOLTS LOW. REMOVED AND REPLACED MAIN BATTERY REF AMM 24-31-01 OPS CK NORMAL ROTABLE PARTS CHANGE WAS INDICATED - TT 1934787 SN OFF 5459 BATTERY, AIRCRAFT OFF 25-2431-9-0001 5459 ON 25-2431-9-0001 1670.