BMW iX Battery Nightmare: Multiple System Failures Surface

Hey! I can relate to your situation. I had similar issues with my 2020 BMW i4 last month. The symptoms you're describing, multiple error messages, start-stop malfunction, and starting issues, are exactly what I experienced. Took it to a certified EV specialist, and it turned out to be the 12V auxiliary battery failure. These batteries typically last 3-4 years, and when they start failing, they cause all sorts of electrical gremlins. The main high-voltage battery was fine, but the auxiliary battery wasn't holding charge properly. The fix wasn't particularly complex, but it required specific diagnostic equipment for BMW EVs. Make sure whoever works on your car has experience with electric BMW models and proper diagnostic tools. The auxiliary battery in these cars isn't just a simple swap like in conventional vehicles, it needs to be properly integrated with the car's systems. Look for a shop that specializes in EVs or, ideally, BMW EVs specifically. Ask about their diagnostic equipment and experience with iX models before committing.

Thanks for sharing your experience! The symptoms do sound identical to what I went through. Just wondering, do you remember roughly how much the auxiliary battery replacement cost you? Also, has everything been running smoothly since the repair, or have you noticed any other quirks?

Hey again! Happy to help update you. Since getting the auxiliary battery sorted out at the EV specialist, my i4 has been running like a dream, absolutely no more electrical gremlins! I paid 290 € for the complete fix, which included the battery replacement and the necessary programming to integrate it with the car's systems. It was definitely worth every penny. All those annoying dashboard warnings disappeared, and the start-stop function works perfectly now. The car starts up instantly every time, just like it should. I'm actually really glad I didn't wait any longer to get it fixed, as it could've potentially led to bigger issues. One thing I learned through this experience is that these modern EVs might be high-tech, but they still rely on that traditional 12V auxiliary battery for lots of basic functions. If you're experiencing the same issues, I'd say go ahead and get it checked out by a qualified specialist. The peace of mind is worth it, and the cost isn't too bad considering what could go wrong if left unaddressed. Let me know if you need any other info about the repair process!

Thanks so much for all the detailed info! Just wanted to update you, I took your advice and found a certified EV specialist. You were spot on, it was indeed the auxiliary battery causing all those problems. Got it replaced yesterday and the car's already running like new. Actually spent less than you did, 250 € for everything. Funny story though, while I was at the shop, the mechanic showed me how the old battery was affecting different systems. He hooked up this fancy diagnostic tool and walked me through all the error codes. Really appreciated how he took the time to explain everything instead of just rushing through the job. It's such a relief not seeing those warning lights anymore! The start-stop works perfectly now, and the car starts up instantly. You really helped me avoid a lot of stress with this one. Thanks again for sharing your experience, it gave me the confidence to get this sorted before it turned into something bigger!