As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PREFLIGHT, BATTERY CHARGER C/B POPPED WITH ODOR/SMOKE IN COCKPIT/CABIN. BATTERY CHARGER REPLACED. UPON TEAR DOWN IN THE SHOP BATTERY CHARGER WAS SEVERELY CHARRED INTERNALLY. THERE WAS SUFFICIENT HEAT TO DISTORT THE ALUMINUM COVER.