What was found
CABIN EMERG LIGHT: WHEN PLANE POWERED UP WITHIN 20 MINS OF SHUTDOWN, THE FOLLOWING EMERGENCY LIGHTS FAILED TO ILLUMINATE: FLOOR SEAT 5 & 8, OVER WIND RIGHT SIDE, AND OVERHEAD SEAT 7 (VERY DIM) WHEN APU STARTED , ALL LIGHTS ILLUMINATED BUT EXTINGUISHED SHORTLY AFTER SHUTDOWN. ***CORRECTIVE ACTION*** GAINED ACCESS TO AND REMOVED INOP #3 EMERGENCY BATTERY AND INSTALLED REPAIRED CONDITION #3 EMERGENCY BATTERY IAW CE680A AMM 33-50-06. PERFORMED 2HR BATTERY CHARGING PROCEDURE IAW CE680A AMM 33-50-00 SECTION C. TECHS ALLOWED EMERGENCY BATTERIES TO STABILIZE FOR L0MIS AFTER THE 2HR CHARGE. TECHS PERFORMED EMERGENCY LIGHTS OPS AND FUNCTIONAL CHECKS IAW CE680A AMM 33-50-00. OPS AND FUNCTIONAL CHECKS GOOD WITH NO DEFECTS NOTED.