As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING 3 SERVICE EMERGENCY EXIT LIGHT TEST, EPSU BATTERY FWD LEFT AND EPSU BATTERY AFT LEFT FAILED. REPLACED EPSU BATTERY AFT LEFT. PASSES BITE TEST ON EPSU. REPLACED EPSU BATTERY OVER DOOR 1L AS PER MM AND ACCOMPLISHED SYSTEM TEST PER MM. SYSTEM OPS NORMALLY.