As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY BATTERY PACK DEFECTIVE AT POSITION M1674. REMOVE AND REPLACE EMERGENCY BATTERY PACK P/N: D717-01-100SWA AND PERFORM OPERATIONAL TEST. / [01] REPLACED EMERGENCY BATTERY PACK AT M1674 WITH SERVICEABLE BATTERY PACK. S/N: WN 1177 PERFORMED OPS TEST; TEST PASSED AS PER B737 AMM 33-51-06-960-806.;[02] VERIFIED STEP 1.