What was found
CREW REPORTED, EMERGENCY LIGHTS WILL NOT STAY ILLUMINATED. MAINTENANCE REMOVED AND REPLACED ALL FOUR EMERGENCY LIGHT BATTERY ASSEMBLIES. OPS CHECKED GOOD IAW EMB145 AMM 33-50-04. AIRCRAFT RETURNED TO SERVICE. P/N OFF 2013-1A; S/N OFF 56460, 72238, 77815, AND 82294.