Mercedes B Klasse Diesel Battery Issues

Wow, that sounds frustrating! I had a similar issue a while back, but not on a Mercedes. Flickering lights are definitely a sign of something wrong with the electrical system. Is the low voltage error consistent, or does it come and go? Maybe check the battery connections to ensure they're clean and tight. Also, what's the battery's age? Sometimes they just give up the ghost.

Thanks for the reply! The low voltage is fairly consistent now. As for the battery age, it's the original one that came with the car. When you say check the connections, are you talking about the main terminals on the battery? I've heard that a bad battery sensor can mess with the charging system. Is that even a thing?

Yeah, I meant the main terminals. Make sure they're not corroded or loose. As for the battery sensor messing with the charging system, that's totally a thing. These cars are so sensitive! It's probably the voltage sensor, since you already getting a low voltage error and symptoms are similar. Honestly, with it being consistent and all, it might be best to get it checked by someone who knows these systems inside and out. It could save you a headache in the long run.

Appreciate the insights! You've confirmed my suspicions about the voltage sensor. Booked it in with a mechanic. Turns out it was the battery sensor. Cost me 315€ to replace, but the car's running perfectly now. Thanks again!