As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE TAXING OF TAKEOFF, EMERGENCY POWER LIGHT ON. AIRCRAFT RETURNED TO THE GATE. MAINTENANCE FOUND LOOSE CONNECTION ON EMERGENCY POWER SUPPLY PACK CONNECTOR. REPAIRED BROKEN WIRE AND REMOVED AND REPLACED EMERGENCY POWER SUPPLY. OPS CHECK GOOD.