As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - DURING PREFLIGHT INSPECTION THE CREW REPORTED A BATT TWO OVERTEMP INDICATION APPROXIMATELY TWO MINUTES AFTER POWER UP WITH THE GPU SELECTED. BATTERY 2 INDICATED 71DEG AND WAS CLIMBING. MAINTENANCE REMOVED AND REPLACED THE NUMBER TWO MAIN BATTERY, OPERATIONALLY TESTED WITH NO DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.