As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW FOUND SMOKE COMING FROM TWO FUSELAGE HOLES FWD OF CTR E/E COMPARTMENT DURING PREFLIGHT INSPECTION. MTC AND FOUND BOTH SHIPS BATTERIES OVERHEATING AND VENTING THRU OVERBOARD VENT TUBES. REPLACED BOTH SHIPS BATTERIES, BATTERY CHARGER AND R2-50 RELAY. BATTERIES AND CHARGER CHECK NORMAL.