As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 9743. "EMERG LT BATT FAULT" EICAS MSG ILLUMINATED ON LANDING. REMOVED FROM SERVICE. INTERROGATED CMC, COMPLY WITH ASSOCIATED FIM TASK 33-50-00-810-804A THROUGH STEP 8J. FOR FAULT CODE 33500004UT1. FERRIED AIRCRAFT FOR REPAIRS. PERFORMED OPS TEST OF AFT RH OUTBOARD EMER. LIGHT POWER UNIT IAW AMM 33-50-01-710-801-A. NO INDICATIONS ON ELPU. REPLACED RH OTBD ELPU BATT IAW AMM 33-50-01-000/400-802-A. ALL RELATED OPS TESTS NORMAL. EICAS MESSAGE REMAINED EXTINGUISHED. ELPU INDICATES NORMAL & CHARGED. NO FURTHER DEFECTS.