As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT CREW PREFLIGHT, FLIGHT CREW RECEIVED 'LOW BATT' ALERT WHEN PERFORMING EMERGENCY LIGHTING TEST. AIRCRAFT REMOVED FROM SERVICE FOR MAINTENANCE. MAINTENANCE PERSONNEL IDENTIFIED LOW BATTERY PACK AND REPLACED IT. OPS CHECK PERFORMED WITHOUT FAULIT. AIRCRAFT RETURNED TO SERVICE. (M)