This depends on how many positioning updates you demand from the tracker. You can control how your device should behave through the BikeFinder app. The app as three different settings for your BikeFinder tracker: Standard, Security, Tracking, Passive. The battery life varies for each setting and it could also depend on the variations in temperature. The battery can last up to 8 weeks in Passive mode.
The BikeFinder tracker has a long battery life in order to work as a security device in case of theft. Therefore it is not possible to request the position of your tracker in the BikeFinder app, because it would require the tracker to constantly be in connection to the internet, which would make the battery run out very quickly. The purpose of BikeFinder is to locate the bike in case of theft. By implementing a long battery life and secure but sparse tracking, we have managed to find 100% of all lost bicycles by using BikeFinder.