BMW i3 Hybrid Shutting Down, Known Issues & Solutions?

Hey there! I've got some experience with hybrids and went through something very similar with my 2020 BMW i4. I'm a casual DIY mechanic, not a pro but familiar enough with hybrid systems. The symptoms you're describing sound exactly like what I dealt with last summer. My car was doing the same unusual shutoffs and the start-stop was acting up. Turned out it was a heavily discharged hybrid battery. Had to take it to my regular workshop since this was beyond my DIY skills. The repair cost me around 290 Euro but it fixed all the issues you mentioned. Before giving more specific advice, could you share: How many miles/kilometers on your i3? Are there any other warning lights besides the main one? Have you noticed any drop in fuel efficiency lately? By the way, if you're having similar symptoms, you might want to get it checked soon. These issues can get worse if left unattended. Hope this helps! Let me know those details and I can share more about what to expect.

Thanks for reaching out! My i3 just hit 13141 KM and had its latest service not too long ago. Actually, I'm seeing the yellow battery warning light, and fuel efficiency has dropped about 15% in the last few weeks. Interesting that you had similar issues with your i4, really appreciate you sharing your experience! Would you mind telling me which specific workshop you used? I'm a bit hesitant about taking it to the dealer since my warranty just expired. Also wondering if you noticed any particular patterns with the shutoffs? Mine seems to happen more when I'm slowing down or at traffic stops.

Hey again! Thanks for the follow-up info! Yeah, those symptoms are crazy similar to what I experienced with my i4. The shutoffs in my case also happened mostly during deceleration and at stops, it's actually a safety feature kicking in when the hybrid system detects something's not right. And that 15% drop in efficiency? That's exactly what I noticed before things got worse. I totally get your hesitation about dealer costs, they wanted to charge me nearly triple what I ended up paying! I went with my trusted independent workshop that specializes in hybrids. Would rather not name them here in the forum, but I can DM you their details if you'd like. One thing I learned from my experience, don't wait too long with this issue. My repair was relatively straightforward because I caught it early. The workshop found that the battery cells were imbalanced and needed recalibration, plus they had to replace one faulty cell. The whole thing took about a day and a half. Given your mileage and the similar symptoms, I'd bet you're dealing with the same problem. Suggest getting it checked asap, these hybrid battery issues tend to snowball if left unchecked. Let me know if you need any other info about my repair experience!

Thanks so much for all the detailed info! Your situation does sound exactly like what I'm experiencing. I'll definitely take your advice and get it checked out right away, those shutoffs are making me really nervous, especially in traffic. I'd really appreciate that DM with your workshop's details! Given how spot-on your description matches my issues, I'd feel much more confident taking it to someone who's successfully fixed this before. The fact that they charged you significantly less than the dealer is a huge plus too. Will probably book it in next week, don't want to risk these problems getting worse like you mentioned. Really glad I posted here and got your insights about the battery cells. It's actually quite reassuring to know there's likely a straightforward fix. Thanks again for all your help! I'll update the thread once I get it sorted out so others can benefit from the solution too.