What was found
DURING A ROUTINE MX CHECK, AN ODOR WAS NOTICED IN THE FWD CABIN, FLIGHT DECK, AND OUTSIDE OF THE ACFT. UPON FURTHER INSPECTION THE FLY BY WIRE BACK-UP BATTERY HAD THE "SMOKING AND OVERHEAT" LED LIGHT ON. THE BATTERY WAS REPLACED IAW AMM, OPS CHECKED GOOD, NO OTHER DEFECTS WERE FOUND.