As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY POWER PACK, M1673, FAILS EMERGENCY LIGHTING FUNCTIONAL CHECK, BATTERY DISCHARGES IN LESS THAN 10 MINS. (REF. AAR NR 99963614). REMOVED AND INSTALLED NEW BATTERY PACK M1673 IAW B737 AMM 33-51-06-960-805, OPS TEST GOOD (WORK ACCOMPLISHED