What was found
DURING CLIMB OUT WE RECEIVED THE EMER LT NOT ARM CAS MESSAGE AND OUR BATTERIES BEGAN TO DISCHARGE. DURING THE SHUTDOWN CHECKLIST THE AIRCRAFT WENT INTO ELECTRICAL EMERGENCY ONCE THE ENGINES WERE SHUT DOWN. REPEAT WRITEUP. FOUND GROUND WIRE AT GS0389 NOT CORRECTLY INSTALLED. A RING TERMINAL WAS NOT INSTALLED ON THE SCREW. RECONNECTED THE RING TERMTNAL WITH NEW HARDWARE. OPS CHECKS GOOD WITH NO DEFECTS NOTED. REF AMM 20-13-21.