As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: DURING BITE CHECK OF THE EMERGENCY POWER SUPPLY UNITS MAINTENANCE FOUND CODES BAT/EPSU (10WL) FWD LBAT/EPSU (14WL) MID R. MAINTENANCE REPLACED BATTERY FOR EMERGENCY POWER SUPPLY UNIT 10WL (AALA202505260166) AND 14WL (AALA202505268312) PER AMM 33-51-38. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.