As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ELEC LIGHT ON RECALL AFTER ENG START. GROUNDED - YES. REF B737-800 FIM 24-31 TASK 801 AND TASK 829 PERFORMED ELECTRIC BITE TEST, FOUND BATT CHARGER FAULT. PERFORMED BATT CHARGER FAULT TROUBLESHOOTING FOUND NO FAULTS WITH WIRING AT MAIN BATTERY AND P5-13 PANEL. CLEANED CONNECTOR AT BATTERY AND CHARGER. ALL FAULTS CLEARED. BATTERY CHARGER OPS NORMALLY.