As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ENGINE ROTATION TOO SLOW AT START ATTEMPTS FOR SUCCESSFUL ENGINE LIGHT OFF. BATTERY VENTED EXCESSIVE AMOUNTS OF SMOKE AND VAPOR (STEAM AND ACID GAS) DUE TO SEVERAL SUCCESSIVE FAILED ENGINE START ATTEMPTS WITHOUT ALLOWING SUFFICIENT RECHARGING BY AIRCRAFT ELECTRICAL SYSTEM. HOT BATTERIES REMOVED FROM AIRCRAFT. STRUCTURE NEUTRALIZED AND RINSED WITH FRESH WATER. - NEW BATTERIES FITTED.