As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ETOPS SIGNIFICANT SYSTEM, AT 4+40 INFLIGHT STATUS ALERT DISPLAYED. EICAS MSG ' MAIN BAT CHGR' DISPLAYED AND MAIN BAT DISCH LGT EXTINGUISHED. MAIN BATTERY VOLTAGE 28V W/NO CHARGER AMP ANOMALIES PRIOR TO EVENT. PERFORMED FIM 24-31-00 "MAIN BAT CHGR" MSG CLEARED. NO FAULTS NOTED. OK FOR SERVICE. PRECAUTIONARY, REMOVED AND REPLACED MAIN BATTERY PER AMM 24-31-01.