As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY POWER SUPPLY L3(M33400) CAPACITY CHECK FOUND LOW REFER HAECO NON-ROUTINE NO.:9437537,ORIGINATED BY EMP:V905393,SPEC NO. B777-33-3-7015. REPLACED EMERGENCY POWER SUPPLY L3(M334 00) AND DO A TEST OF THE NEW BATTERY PACK, THE RESULT FND "NORMA L" AS PER AMM 33-51-06-9620-802 REV.91.