What was found
WHILE EN ROUTE TO KADS FROM KHPN AT 45,000 FEET, APPROXIMATELY 1.5 HOURS INTO OUR FLIGHT, THE BATT 2 DISCHARGING CAS MESSAGE ILLUMINATED. THE EMER BUS 2 WAS POWERED BY BATT 2 ONLY, THE AUTOMATIC BUS POWER TRANSFER FAILED CAUSING A CASCADE OF SYSTEMS TO FAIL. AN EMERGENCY WAS DECLARED, AN UNSCHEDULED LANDING MADE AT KCVG. EXTENSIVE TROUBLESHOOTING COULD NOT IDENTIFY THE EXACT CAUSE OF THE FAILURE; HOWEVER, THE MOST LIKELY CAUSE WAS EITHER THE EMERGENCY POWER DISTRIBUTION CABINET 2 (EMPC2) OR THE RIGHT POWER DISTRIBUTION CABINET (RPDC), BOTH WERE REMOVED AND REPLACED. OPERATIONAL TESTS OF THE ENTIRE ELECTRICAL POWER DISTRIBUTION SYSTEM FOUND NO ADDITIONAL ISSUES.