What was found
EMER LIGHTS FAIL TO TEST DURING PREFLIGHT. RAN QRH, AND CHARGED BATTERY PACKS, POWERED DOWN, AND THE EMER LIGHTS PASSED TEST. PLANE WAS SHUT DOWN FOR 1.5 HOURS AFTER FLIGHT, AND EMER LIGHTS FAILED TEST. RAN QRH AGAIN TO PASS TEST. BATTERY PACKS ARE NOT HOLDING CHARGE LIKE THEY SHOULD. CORRECTIVE ACTION: REPLACED EMERGENCY BATTERY'S OPS CHECK GOOD ALL WORK COMPLETED IAW CESSNA 700 AMM 33-50-07