As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RECEIVED L BATTERY OVER TEMP CAS MESSAGE AFTER TAKEOFF. RAN QRC & QRH AND BATTERY TEMPERATURE SLOWLY CAME DOWN. RETURNED BACK TO MDW. REMOVED DEFECTIVE BATTERY AND REPLACED WITH SUPPLIED OVERHAULED BATTERY IAW AMM 24-30-05. OPS CHECKED GOOD. COMPLIED WITH MAIN BATTERY INSTALLATION DUE TO BATTERY CHANGE REV 4 DATED 03 JUN 2020 IAW C68-24-0001_1.