As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED COMPLETE ELECTRICAL FAILURE. DURING TROUBLESHOOTING, THE BATTERY WAS FOUND TO HAVE NO CHARGE AND THE RIGHT ENGINE STARTER WAS STILL ENGAGED AT THE BENDIX. FURTHER TROUBLESHOOTING FOUND THE STARTER TOGGLE SWITCH WAS STUCK IN THE ON POSITION FOR THE RIGHT ENGINE CAUSING THE STARTER TO REMAIN ENERGIZED AFTER ENGINE START UNTIL IT SHORTED OUT, DRAINING THE ELECTRICAL SYSTEM TILL FAILURE.