BATTERY EXPLODED WHEN IGNITION TURNED ONE CLICK TO "ON" POSITION. VEHICLE WAS IN GARAGE. HEARD A BOOM WHEN I TURNED KEY. OPENED HOOD TO SEE SMOKE AND A DAMAGED BATTERY. CAPS WERE BLOWN CLEAR, TOP OF CELL WAS CRACKED IN 4 PLACES. BATTERY ACID SPRAYED HOOD AND SURROUNDING AREA.*AK