BMW i3 Hybrid Battery and Power Issues Need Help

Hey there! I had nearly identical issues with my 2016 BMW i8 Hybrid last year. The symptoms were spot on with what you're describing, sluggish performance, dim lights, and starting problems. Initially thought it was just the battery, but the diagnosis revealed a defective generator (alternator). The repair wasn't simple since these hybrid systems are pretty complex. My generator had failed due to a faulty voltage regulator, which was affecting both the conventional charging system and the hybrid battery management. They had to remove several components just to access the generator assembly. The fix required a complete generator replacement plus recalibration of the hybrid system. It was definitely a serious issue that needed immediate attention, driving with a failing generator can damage other electrical components and leave you stranded. One tip: Make sure the shop has experience with BMW hybrid systems. This isn't a repair for a general mechanic. My generator had a 6-month warranty on the part and labor, which was reassuring. Hope this helps with your situation.

Thanks for sharing your experience! That sounds exactly like what I'm going through right now with my i3. Quick question, do you remember roughly how much you ended up paying for the whole repair? Also, has everything been running smoothly since the fix, or have you noticed any other electrical gremlins popping up? Just want to know what I might be in for, both cost-wise and if I should expect any other issues down the road. Thanks!

Hey again! Happy to help! Yes, I remember exactly what I paid, it was 960 € for the complete generator replacement and recalibration. I know it sounds steep, but considering the complexity of these hybrid systems, it was actually reasonable for the work involved. And I've got good news for you, since getting it fixed at the mechanic, my i8 has been running like a dream! All those annoying symptoms completely disappeared. The engine's got its pep back, lights are bright and steady, and the battery's holding charge perfectly. No more electrical gremlins whatsoever. It's been about a year now, and I haven't had a single issue with the charging system. Trust me, once you get that generator sorted, you'll notice the difference immediately. Just make sure you get it done by someone who knows their way around BMW hybrids. Might save you some headaches down the road. Let me know how it goes with your i3, always interested to hear how these repairs turn out for others!

Thanks so much for all the detailed info! I actually just got back from the mechanic today. You were absolutely right about finding someone who specializes in BMW hybrids, made a huge difference. The guy I found really knew his stuff and spotted the issue right away. Funny enough, my repair bill came in pretty close to what you paid. The generator was shot, just like you said. They had to do some extra work to get to it, but the mechanic walked me through everything they were doing. Even showed me the old part, it was definitely toast! The best part? The car's running perfectly now! Started right up, all the lights are bright, and that sluggish feeling is completely gone. What a relief! The mechanic also gave me a solid warranty on the work, which makes me feel much better about the investment. Really appreciate you sharing your experience, helped me avoid getting ripped off and find the right mechanic for the job. Thanks again for all your help!