BMW i4 High-Voltage System Failures: Causes & Solutions

Hey! I have some experience with EVs and went through something very similar with my 2018 BMW i3 (also had an i4 before). Had the exact same symptoms, power cuts, reduced performance, and that annoying high-voltage warning. Took it to my regular workshop and it turned out the battery was severely discharged and showing signs of deterioration. They ran a full diagnostic, and after confirming the battery issue, they had to recalibrate the entire system. The fix cost me 290 Euro but totally worth it, car's been running perfectly since then. What's your current mileage and have you noticed any other warning lights? Also, how long have you been experiencing these issues? This info would help me understand if you're facing the same problem I had. Just make sure to get it checked soon, driving with a faulty battery system isn't great for the car's overall health.

Thanks for sharing your experience! Mine's at 150915 KM since my last service a few weeks ago. Been dealing with these issues for about 2 weeks now. No other warning lights except the high voltage one. Starting to think it might be the same battery problem you had. Good to know there's a potential fix, though hoping it won't cost too much. Going to book it in for a check tomorrow, really can't risk having it shut down while driving.

Hey again! Yeah, those symptoms at 150k+ km definitely sound familiar, almost exactly what I experienced. Since you mentioned it's been happening for about 2 weeks, it's pretty much identical to how mine started acting up. Actually, what got me really concerned back then was exactly what you mentioned, the unusual shutdowns while driving. That's what pushed me to get it checked immediately. Smart move booking it in tomorrow. The high voltage warning being the only light is actually a good sign, when I ignored mine initially, I ended up with multiple warning lights after a few days. The repair cost might vary a bit from what I paid (290 Euro), but from what I remember, the main expense was the system recalibration rather than any parts. The battery wasn't completely shot in my case, just needed some serious TLC. Would be interested to hear what they find when you get it checked. If it's the same issue, the fix should be pretty straightforward. Just make sure they do a full diagnostic, that's what caught the problem with mine before it got worse. Let me know how it goes! Always good to share these experiences so we can help each other out with these EVs.

Really appreciate all the detailed info! You've actually made me feel a lot better about the whole situation. It's super helpful knowing someone else went through the exact same thing. The repair cost doesn't sound too bad either, I was honestly expecting much worse! The workshop confirmed they can take a look at it first thing tomorrow morning. I've made notes about your experience to share with them, especially about the system recalibration part. You're right about getting it sorted quickly before more warning lights start popping up. I'll definitely keep you posted about what they find. Thanks again for all your help, it's really reassuring to know it's likely a fixable issue and not something more serious. Hope my experience can help others too when they run into similar problems with their EVs!