As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITH EMER LIGHT SWITCH IN ARM POSITION EMER LIGHTS ON FROM ROW 12 TOWARDS BACK. PREVIOUS WRITE UP PG 3688619. R & R NR 4 BATTERY POWER SUPPLY & BATTERY PACK IAW AMM 33-50-04. OPERATIONS CHECKED GOOD. EMER LIGHTING BATTERY PN 2013-1A SN 66556.