As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING 4-DAY CHECK, FUNCTIONAL TEST OF EMERGENCY LIGHT SYSTEM THE FORWARD LT EMERGENCY LIGHT BATTERY FAILED TEST AT EMERGENCY POWER SUPPLY UNIT (10WL). MAINTENANCE REMOVED AND REPLACED EMERGENCY LIGHT BATTERY PACK AT EMERGENCY POWER SUPPLY UNIT (10WL), OPERATIONAL CHECK WAS GOOD.