As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER BLOCK IN IRS NR 1 BATTERY FAIL LIGHT ILLUMIN W/ ASSOCIATED CAUTION MSG APU DID NOT ST AND BATTERY VOLT READ 10 VOLTS ALSO NOTED ACRID ELECTRICAL ODOR IN COCKPIT AND FIRST CLASS CABIN. REPLACED BATTERY CHARGER BATTERY CHARGER RELAY R2-56 AND 3 SHIPS BATTERIES. NO HELP FOUND APU START RELAY SHORTED REPLACED SAME BATTERY CHARGE OPS CHECK NORMAL APU STARTS NORMAL ALSO REPLACED LT AND CTR BATTERY CONNECTOR.