As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING THE PREFLIGHT CHECK FOR FLIGHT 3768 THE CREW NOTICED ALL EMERGENCY LIGHTS DEAD AND FOUND THE SWITCH IN THE ON POSITION. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED ALL OF THE EMERGENCY POWER SUPPLY BATTERY PACKS IAW CRJ 700 MM CH 33-51-17. PART NUMEBR: 20131-A. SERIAL NUMBERS: 66432, 105194, 104854 AND 77338. THE AIRCRAFT WAS RETURNED TO SERVICE.