The radio will run app 10 minutes before shutting down after the engine is switched off. But once the radio turns off after giving a warning, you can just hit the on /off button and the radio will run again for a shorter time. But open the drivers door and the car naturally assumes you have left for the day. All in the sake of saving the battery. My Merc would run 30 minutes before shutting off the radio and the reading lights. I could also have the seat heaters running without the engine running and never had a problem with the battery