As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN BATTERY VOLTAGE LOW, ACFT GROUNDED. REPLACED MAIN AND AUX BATTERIES IAW AMM 24-31-11. BATTERY REPLACEMENT NO HELP. REPLACED MAIN BATTERY CHARGER IAW AMM 24-31-21. BATTERY CHARGER OPS CHECK GOOD IAW AMM 24-31-21. PERFORMED MAIN & AUX BATTERY OPS CHECK IAW AMM 24-31-11, OPS CHECK GOOD.