What was found
ON FLIGHT 3888 THE CREW REPORTED THE EMERGENCY LIGHTS ON STATUS CAME ON WENT OUT AFTER ABOUT AN HOUR AIRBORNE. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED NR 1 AND NR 3 EPSU BATTERY PACKS AND CHARGERS IAW CRJ700 AMM 33-51-17. PART NUMBER NR 1 BATTERY 2013-1A, S/N 103799. PART NUMBER NR 1 CHARGER 11-0049, S/N 13258. PART NUMBER NR 3 BATTERY 2013-1A S/N 85530. PART NUMBER NR 3 CHARGER 11-0049 S/N 12641. PART NUMBER NR 1 BATTERY 2013-1A S/N 105216. THE OPERATIONAL CHECKS WERE GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.