Thanks for posting and welcome to the Bose Community. I would love to answer any questions you may have about your speaker!
This isn't something that can be adjusted on the speaker, it will turn off after 30 minutes of inactivity to save power when the speaker isn't being used. I would be more than happy to raise this for you as a future feature request as something to be added down the line.
If you or any other users have any other feature suggestions please do let us know.