As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY LIGHTS AT SEATS 8 ABC, AND 9-18 DEF WENT OFF PRIOR TO 15 MINS. ACFT GROUNDED. R & R, AND TESTED EMERGENCY EXIT LIGHT BATTERY PACKS AT BS 603 LT & RT, SIDEWALL IAW MM 33-51-06-960-805. TESTS PASS, OK FOR SERVICE. BATTERIES INSTALLED AT 03:00.