As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING THE WEEKLY CHECK, THE EMERGENCY LIGHTS TEST FAILED WITH AN 'EPSU BATTERY R' MESSAGE. MAINTENANCE REPLACED THE RIGHT OVERWING EMERGENCY POWER SUPPLY UNIT BATTERY, AND PERFORMED THE EMEGENCY LIGHTS TEST. OPERATIONALLY CHECKED OK. (M)