As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
REF NR L/P 9469640 - SPEC NO. B777-33-3-7019 - DURING EMER PWR PACK CAPACITY CHK FOUND DR 4R M33409 BATTERY LOW VOLTAGE EMER LWR PACK ON DR 4R M33409 REPLACED, NEW BATTERY PACK TEST FA RRIED OUT FOUND MORMAL, REF AMM 33-51-06-960-802 REV.84 ADD EMP:V903182 IDT BY TA646