As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AC SUFFERED ALMOST AN ENTIRE ELECTRICAL FAILURE DURING CLIMBOUT. AFTER SUBSEQUENT UNSCHEDULED LANDING, IT WAS DETERMINED THAT THE BATTERY HAD ACQUIRED AN INTERNAL SHORT, WHICH DEPLETED THE GENERATOR OUTPUT AND CAUSED THE AVIONICS TO MALFUNCTION. BATTERY REPLACED WITH A SERVICEABLE SPARE, AND AC ELECTRICAL SYS CONFIRMED OPERATIONAL. (TC NR 20071128012)