As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DEN/COD - FLT 7708 - DURING CLIMB-OUT, MAIN BATTERY TEMPERATURE INCREASED RAPIDLY. THE CREW TURNED THE BATTERY OFF PER THE QRH. TEMPERATURE CONTINUED TO INCREASE ABOVE RED LINE. THE CREW DECLARED AN EMERGENCY AND DIVERTED TO LAR. MAINTENANCE REMOVED AND REPLACED THE MAIN BATTERY, OPS CHECK GOOD. AIRCRAFT RETURNED TO SERVICE. (X)