As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT EMERGENCY LIGHTS CAME ON, WHEN POWER WAS OFF AND EMERGENCY LIGHT SWITCH WAS OFF DURING SCHEDULED REPLACEMENT OF NEW BATTERIES. FOUND NEW BATTERY ON RT AFT POSITION DEFECTIVE. REMOVED AND REPLACED RT AFT ELPU IAW AMM 33-50-01, OPS CHECK OK.