As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, AIRCRAFT LOST ELECTRICAL POWER FROM RIGHT BATTERY. MAINTENANCE DISCOVERED THE RIGHT BATTERY WAS DESTROYED BY THERMAL RUNAWAY. THE HEAT FROM THE RIGHT BATTERY ALSO DESTROYED LEFT BATTERY. BATTERIES WERE BOTH REPLACED WITH LEAD ACID BATTERIES.