As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 7770 - OAK TO LAX - FLIGHT CREW DECLARED EMERGENCY IN FLIGHT DUE TO BATTERY NR 2 OVERHEAT TO 80 DEGREES F. CREW LANDED IN LAX WITHOUT INCIDENT. MX PERSONNEL REMOVED AND REPLACED NR 2 MAIN BATTERY OPERATIONALLY CHECKED WITH NO DEFECTS AND A/C WAS APPROVED TO RETURN FOR SERVICE.