As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - APU BATT CHARGER STATUS MESSAGE. RETURNED TO SEA. LANDING UNEVENTFUL. REMOVED AND REPLACED APU BATTERY AND APU BATTERY CHARGER IAW CRJ-700 AMM TASKS 24-32-03-000-801; 24-32-03-400-801; 24-32-07-000-801 AND 24-32-07-400-801. OPS CHECK GOOD. APU BATT CHARGER MESSAGE DID NOT ILLUMINATE. RETURNED TO SERVICE.