Mercedes Viano Diesel Weak Battery Issue

Oh my goodness, that sounds awfully familiar! I have a Vito, and I had some very similar symptoms not too long ago. Flickering lights drove me absolutely mad! I was constantly worried about whether my battery would leave me stranded. Did your diagnostics specifically mention the battery voltage sensor, or just a general battery issue? What kind of readings are you getting for your battery voltage when the engine is off and when it's running?

The vehicle diagnostics reported a fault in the battery sensor circuit. I haven't measured the battery voltage myself. Was your issue definitively the voltage sensor?

Yes, eventually the workshop confirmed it was indeed the voltage sensor. It was causing all sorts of havoc with the battery charge readings and, consequently, the vehicle's electrical system. Given your symptoms and the diagnostic report, it's highly probable you're facing the same issue. I would strongly recommend taking it to a reputable workshop for confirmation and repair. Ignoring it could potentially damage other components.

Thanks for confirming. I appreciate the advice. I had the battery sensor replaced. Total cost was 315€. Problem solved.