As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 3998 THE CREW REPORTED, UNABLE TO ESTABLISH AIRCRAFT POWER AND SUSPECT MAIN BATTERIES 1 & 2 TO BE DEAD. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED THE MAIN BATTERIES 1 AND 2 IAW EMB AMM 24-36-01. THE OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.