As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW OBSERVED DC FAIL LIGHTS ON THE INERTIAL REFERENCE UNITS. THE CREW THEN OVERSERVED LOW VOLTAGE ON THE AIRCRAFT MAIN BATTERY AND DIVERTED TO A NEARBY AIRPORT. AFTER LANDING, THE ONBOARD MECHANIC OBSERVED ELECTRICAL CONNECTOR D2936 HAD BECOME DISCONNECTED FROM THE BATTERY. THE BATTERY AND BATTERY CHARGER WAS REPLACED AND THE SYSTEM OPS CHECKED GOOD AND AIRCRAFT RETURNED TO SERVICE.