the stereo in my 2011 SmartCar Passion has stopped working

What is your question?

Not battery related. The Smart logo appears on the system screen, then a minute or so later the unit appears to shut down, then after another pause it comes back on and the same thing happens. This sequence just repeats and repeats :( There have not been any changes or maintenance recently

What makes this problem better or worse?

It doesn't change

How long has your 2011 Smart Fortwo had this problem?

a couple of weeks