BMW i4 Electrical Issues? Check Terminal 30 First

Hey there! I have some experience with EVs and had a similar issue with my 2019 BMW iX3 (love the BMW EVs, almost went for the i4 myself!). When I had those exact symptoms, low battery warnings and starting problems, it turned out my 12V battery was totally drained. The main high-voltage battery was fine, but the 12V auxiliary battery that powers the electronics was the culprit. Took it to my trusted workshop and they diagnosed it as a deeply discharged battery that was beyond recovery. Total fix was 290 Euro including a new battery and programming. Been running perfectly since then, about 8 months now. What's your mileage and are you seeing any other warning lights? Also, how long have you had these symptoms? This info would help better understand if you're facing the same issue I did. Feel free to share more details, always happy to help a fellow BMW EV owner!

Thanks for sharing your experience! I'm at 74374 KM on my i4 and just started noticing these issues about a week ago. Haven't had any major problems since my last service. Your battery situation sounds very similar to what I'm experiencing. Did you notice any correlation with cold weather or did it just happen out of nowhere? I'll definitely get the 12V battery checked first before looking into more complex issues. Really appreciate the detailed explanation about your repair, gives me hope it might be a straightforward fix.

Hey again! Yeah, temperature definitely played a role in my case. I noticed the issues became more pronounced during cold weather, it's like the cold was the final straw for my aging 12V battery. In my case, it started out of nowhere with occasional warning messages, but the cold weather made it much worse. The car would struggle more to start in the mornings, and those battery warnings became more frequent. It's pretty typical for 12V batteries to show their weakness in colder conditions. Your mileage is pretty close to what mine was when I had the issue (I was around 68000 KM). The symptoms appearing suddenly within a week is also very similar to my experience, it kind of snowballs once the battery starts failing. Just a heads up, after my battery replacement, the workshop mentioned it's good practice to take the car for longer drives occasionally. Apparently, lots of short trips don't give the 12V battery enough time to fully recharge, which can contribute to these issues. Let me know how it goes after you get it checked. I'd bet money it's the same issue I had with the 12V battery. The repair should be pretty straightforward if that's the case.

Thanks so much for all this detailed information! You're absolutely right about the cold weather connection, now that you mention it, these issues did start when temperatures dropped. Your experience is incredibly helpful, especially knowing the repair was straightforward for you. I've scheduled an appointment with my workshop for next week to check the 12V battery. I'll definitely follow your advice about those longer drives too, makes total sense about the charging time. It's really reassuring to hear that such similar symptoms were resolved with a simple battery replacement in your case. I was worried it might be something more serious with the electrical system. The cost you mentioned seems reasonable too, especially compared to what I was imagining. I'll update the thread once I get it sorted, but I'm feeling much more optimistic now. Really appreciate you taking the time to share all these details!