Mobilio weak battery defective sensor

Hey there! Weak starts and flickering lights definitely point towards battery issues. Have you checked the battery voltage when the engine is off and running? That could give you an idea if the sensor is reporting wrong data. It could also indicate a problem with the alternator not charging the battery properly, a classic issue in my experience.

Thanks for the tip. Where exactly should I measure to get a good reading, and what values am I looking for with the engine both off and on?

No worries! You'll want to measure directly at the battery terminals. With the engine off, you should be seeing around 12.6V. When it's running, the voltage should climb to somewhere between 13.7V and 14.7V. If it's outside this range, or very unstable, the charging system isn't working correctly. Given the symptoms and your mileage, and you've already investigated a bit, it's probably best to get it professionally diagnosed; a bad sensor can cause a lot of headaches, and it might be worth ruling out the alternator or a parasitic draw at the same time.

Alright, thanks a lot for the detailed advice. I took it to a workshop, and it turned out to be a defective battery sensor, as suspected. Ended up costing me 315€ to replace. Runs like new now, appreciate the help!