BMW i4 Battery Drain Causing Multiple System Failures

Had the same issue with my 2018 BMW iX3 last month. Turned out the 12V auxiliary battery was failing, not the main high-voltage battery. The symptoms matched yours exactly, dim lights, flickering dash, and system malfunctions. Got it checked at a certified EV service center. They ran diagnostics and found the auxiliary battery wasn't holding charge properly anymore. It's a pretty common issue with EVs, especially when they're regularly parked for extended periods. The fix involved replacing the auxiliary battery and recalibrating the battery management system. Wasn't a huge repair job, but definitely needed professional attention since it affects multiple vehicle systems. If you're looking for a new shop, make sure they're specifically certified for EV repairs. My repair went smoothly and the car's been running perfectly since. Just make sure to get it checked soon, driving with a failing auxiliary battery can cause more serious electrical system issues down the line.

Thanks for sharing your experience! That's super helpful, I've been worried it might be something more serious with the main battery. Your symptoms sound exactly like what I'm dealing with. I'm gonna look into getting the auxiliary battery checked at a certified EV place. Just wondering, do you remember roughly how much you ended up paying for the whole repair? And has everything been working fine since then, or have you noticed any other quirks?

Hey again! Glad I could help with my previous advice! Yes, everything has been running perfectly since I got it fixed. The undervoltage issue was completely resolved after they replaced the auxiliary battery. The total bill came to 290 €, it covered both the battery replacement and the system recalibration work. Honestly, it was worth every penny considering how smoothly the car runs now. Haven't noticed a single quirk since the repair. No more flickering dash lights, no starting issues, and all systems are working just as they should. It's like having a new car again! The technicians explained that catching it early probably prevented any additional problems from developing. If your symptoms are like what I had, you're definitely on the right track looking into the auxiliary battery. Just make sure you get it done at a place that knows their way around EVs, it makes a huge difference in the quality of work you get. Let me know how it goes when you get yours checked out!

Thanks everyone! Just wanted to update you on what happened. You were absolutely right about the auxiliary battery. I finally got my car checked at a certified EV service center yesterday. The diagnostic confirmed it was indeed the 12V battery causing all those issues. The whole experience was actually pretty smooth. The technicians were super knowledgeable and explained everything clearly. They replaced the battery and recalibrated the system, took about two hours total. Cost me around 300 bucks, which wasn't as bad as I feared. Took it for a drive this morning and what a difference! No more flickering lights, all systems working perfectly, and it starts up like a charm. Such a relief it wasn't anything major with the main battery. Really glad I asked here first, saved me a lot of worry and helped me find the right place to get it fixed. Thanks again for all the advice. Definitely keeping this shop in mind for future services!