BMW Battery Sensor Issues Causing Multiple Failures?

Hey there! I had nearly identical issues with my 2018 BMW 7 Series 730d last winter. The symptoms you're describing match exactly what I experienced, battery warnings, struggling to start, and those annoying light fluctuations. Initially thought it was just the battery, but when I took it to the garage, they diagnosed a faulty Intelligent Battery Sensor (IBS). It's a crucial component that monitors the battery's charge state and controls the charging system. The sensor wasn't sending correct data to the car's computer, causing all those warning messages and charging issues. Got it fixed by replacing both the sensor and its wiring harness since there was some corrosion. The repair wasn't particularly complicated, but it's definitely not a DIY job because it needs proper coding to the car's system. After replacement, all those issues disappeared completely. This is actually a serious issue that needs attention soon, ignoring it could leave you stranded or cause damage to other electrical components. Hope this helps with your decision!

Thanks for sharing that! Yeah, it sounds exactly like what I'm dealing with. Quick follow-up, do you remember roughly how much the repair set you back? And has everything been running smoothly since, or have you had any other electrical gremlins pop up? Just trying to get an idea of what I'm in for.

Hey again! Just wanted to follow up, yes, I got the battery sensor fixed and it cost me 315 € in total. Best money I've spent on the car honestly! Since getting it sorted, everything's been running like a dream. No more warning lights, no more starting issues, and all the electrical stuff is working perfectly. It's been about 8 months now since the repair and I haven't had a single electrical gremlin show up. The lights are nice and bright, and my car starts up first time, every time. Such a relief after dealing with all those annoying symptoms before. Trust me, it's worth getting it fixed properly. I'm actually glad I didn't try any quick fixes or keep putting it off. The mechanic mentioned that leaving it unfixed could've caused bigger problems down the line. Let me know if you need any other info about the repair, happy to share more details from my experience!

Thanks so much for all the details! I actually bit the bullet and took my car to a mechanic yesterday. You were spot on, it was the battery sensor causing all the trouble. Ended up paying around 300 € for the fix, pretty much what you mentioned. The mechanic was great actually, showed me the old sensor and explained everything. They got it done in about two hours, and wow, what a difference! The car starts up perfectly now, no more flickering lights, and that annoying warning light is finally gone. Can't believe I was stressing about this for so long. Should've done it sooner! Really appreciate you sharing your experience, it gave me the push I needed to get it sorted. The mechanic even mentioned I caught it at a good time, before it could cause any other issues. Fingers crossed it stays problem-free like yours has. Thanks again for all the help!