Hey, I had a similar problem with my 2010 Benz GL Class. I'm not a professional, but I do deal with cars a bit. My garage found a faulty control unit, which was the cause of the self-discharging battery. The repair cost me 600 euros. To be able to help you better, I would need some more information about your vehicle. How old is your battery and when was the last time the alternator was checked? Have you recently made any changes or modifications to your car?

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Hey, thanks for your quick reply! The control unit really could be the culprit, I hadn't even considered that. My battery is only a year old and the alternator was checked at the last inspection 198958 km ago. I didn't notice anything unusual. I haven't actually made any changes or modifications. Perhaps I really should visit the garage. Thanks again for the tip!

(Translated from German)

No problem, always happy to help! It really sounds as if the control unit could be the culprit. With a year-old battery and an alternator that was checked almost 200 km ago, I would definitely recommend having both checked in the workshop. You don't want to break down at some point because the battery suddenly gives up the ghost. It wouldn't hurt to have the electrics checked either. Incidentally, after replacing the control unit in my GL, I no longer had any problems with self-discharge or flickering lights. So you'd better have it checked. Good luck and let us know how it goes!

(Translated from German)

Wow, thanks for your advice! I guess you're right, I shouldn't take this lightly. Before I get stuck here, I'll follow your advice and call my garage to have the battery, alternator and electrics checked. A faulty ECU could well be the problem - good to know I'm not the only one who has struggled with this. I'll keep you posted on how it turns out. Thanks again for your help!

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