BMW i8 Battery Woes: Help Finding Hybrid System Expert

Hey there! I faced almost identical symptoms with my 2015 BMW i3 Hybrid last season. The startup struggles and system warnings are typical signs of a failing 12V auxiliary battery, not necessarily the main hybrid battery pack. When I took mine in, the diagnostic confirmed severe battery degradation affecting multiple systems. The 12V battery in these hybrids works extra hard managing all the electronics, and they tend to fail earlier than in conventional cars. Mine was shot after about 115,000 KM. Had to get the 12V battery replaced along with a full system diagnostic reset. This fixed all the issues, no more flickering lights, weird error messages, or startup problems. It turned out to be a serious but straightforward fix. If you're getting undervoltage errors, don't wait too long as it can potentially damage other electrical components. These hybrids need specialists who understand the dual battery systems. The 12V battery issue is quite common in BMW hybrids, and I'd bet that's what you're dealing with.

Thanks for sharing your experience! That sounds exactly like what I'm dealing with. The symptoms are spot on, and it's reassuring to know it might just be the 12V battery rather than something more serious. Would you mind sharing roughly how much you ended up paying for the battery replacement and reset? Also curious if you've had any other electrical gremlins pop up since getting it fixed?

Hey again! Happy to let you know that after getting my i3 fixed, everything has been running perfectly smooth! Haven't seen a single electrical gremlin since the repair, and that pesky undervoltage warning is completely gone. The total bill came to 290 €, that covered the battery replacement and the system reset. Honestly, it was worth every penny considering how much better the car runs now. No more heart-stopping moments wondering if it'll start or dealing with those annoying flickering lights! Just so you know, these high-tech hybrids can be pretty sensitive when the 12V battery starts going bad. But once you get it sorted, they're really reliable. Mine's been rock solid for the past several months, starts right up every time, all systems working exactly as they should. Trust me, once you get it fixed, you'll wonder why you didn't do it sooner. The peace of mind alone is worth it. Let me know how it goes when you get yours sorted!

Update: Finally got my i8 sorted out! Took your advice and had the 12V battery replaced. The whole thing was way less painful than I expected. Found a great mechanic who specializes in hybrids. He confirmed right away it was the auxiliary battery causing all those weird electrical issues. Got it fixed in about two hours, new battery installed and systems reset. Bill came to a bit more than yours at 340 €, but totally worth it. Car's running like new now! No more flickering lights, unusual warnings, or startup problems. Can't believe I was stressing so much about it. Such a relief knowing it wasn't something more serious with the main hybrid system. Really appreciate everyone's help here. Definitely learned my lesson about not waiting too long when these electrical issues pop up. Next time I'll know exactly what to look for! Thanks again for pointing me in the right direction!