As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
REF LP442391-1. BATTERY EPSU (EMERGENCY LIGHTING POWER SUPPLY) 10WL FAULTED DURING A SCHEDULED MAINTENANCE CHECK. CORRECTIVE ACTION: PERFORMED OPERATIONAL CHECK AND BITE CHECK OF EPSU PER TSM 33-51-00-810-822-A. TESTS AND BITE CHECKS WERE GOOD. NO FAULTS NOTED. A/C READY FOR CONTINUED SERVICE.