As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING AIRCRAFT REPOSITIONING GOT ELEC LIGHT ON OVERHEAD PANEL WITH SUBSEQUENT BATT DISCHARGE LT. GROUNDED - YES. PERFORMED ELEC LITE BITE TEST PER B737-800 FIM 24-31 TASK 801 AND NOTED BAT CHARGER INOP MAINT MESSAGE. REPLACED MAIN BATTERY CHARGER REF B737-800 AMM 24-31-21 AND OPS CHECKED PER AMM 24-31-21-710-801. ALSO PERFORMED REPAIR CONFIRMATION REF FIM 24-31 TASK 829 ALL TESTS PASSED.