As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN BATTERY CHARGER MSG DISPLAYED LOWER EICAS. UNABLE TO ERASE. SWAPPED MAIN BATTERY CHARGER WITH APU BATTERY CHARGER. MAIN BATTERY CHARGER STATUS MESSAGE CLEARED. APU BATTERY CHARGER NOW INOP. NEEDS APU BATTERY CHARGER. REPLACED AND OP CHECKED MAIN BATTERY. MAIN BATTERY CHECKS GOOD.