As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
YYT - INFLIGHT MAD-MIA. AUXILIARY POWER UNIT BATTERY OVER TEMPERATURE LIGHT ILLUMINATED. EMERGENCY DECLARED, LANDED YYT WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED AUXILIARY POWER UNIT BATTERY CHARGER. SYSTEM GROUND CHECK NORMAL OPERATION.