How long will my smartwatch battery last? Updated May 22, 2019 09:31 Follow Your battery will last up to 24 hours, depending on usage. Related articles How do I conserve battery life? What is the warranty on my smartwatch? How long does it take to charge my smartwatch's battery? How can I contact Fossil Customer Care by email? My battery won't change past a certain percentage. How can I fix this? Comments 0 comments Please sign in to leave a comment.