As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW RECEIVED A BATTERY AND BATTERY CHARGER STATUS MESSAGE AT LEVEL OFF AFTER DEPARTING IAH. THE MESSAGES WERE ACCOMPANIED BY A STRONG ELECTRICAL SMELL IN THE COCKPIT. THE AIRCRAFT WAS RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE MAIN AIRCRAFT BATTERY AND BATTERY CHARGER IAW MM 24-31-01.