As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMELL OF SMOKE IN CABIN. FOUND SOURCE OF SMELL AND SMOKE AS APU BATTERY VERY HOT AND ODOR THE SAME AS WHAT WAS IN CABIN AREA JUST ABOVE THE E6 RACK. REPLACED APU BATTERY AND APU CHARGER PRECAUTIONARY. ALSO, REPLACED K116 RELAY PRECAUTIONARY. OPS CHECK NORMAL. NO ODORS OR SMOKE.