As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING WC #3351-2001, MAINTENANCE FOUND ONE EMERGENCY LIGHT BATTERY TO BE BAD FROM STOCK. INSTALLED ORIGINAL EMERGENCY LIGHT BATTERY (B5-227) IAW B717 AMM 33-51. DEFERRED FOR 40 FLIGHT HOURS. 28NOV19 DTW - THE EMERGENCY LIGHT BATTERY PACK (B5-227) WAS REPLACED PER WC #3351-2001. OPERATIONAL CHECK WAS GOOD. (LP #6404530)