Agreszler

I have a 2019 Sprinter 2500 van that I converted to a motor home. I purchased a subscription so I have internet access and a hotspot. I would like to use this with the engine off. After engaging the start button (without braking so engine does not start) the media system will run for about 10 minutes then shut off. I'd like it to run much longer. Is there any way to accomplish this? Will there be a warning if the battery is low?