BMW i8 Battery Woes: Starting Issues & Error Alerts Mount

Hey there! I had nearly identical issues with my 2020 BMW i3s last month. The symptoms were exactly like yours, unusual dash warnings, start-stop system failing, and difficult starts. After taking it to the garage, they diagnosed it as a failing auxiliary battery, which was draining faster than normal. The main issue was that the auxiliary battery wasn't holding charge properly anymore, affecting all the car's electronic systems. This is actually quite common in hybrid BMWs after high mileage. The fix wasn't too complicated, they replaced the auxiliary battery and recalibrated the battery management system. What seemed like a major electrical problem turned out to be pretty straightforward. Just make sure they use the correct battery type with proper coding to the car's computer. Definitely not something you want to ignore though, as a failing auxiliary battery can eventually prevent the car from starting altogether and potentially cause other electrical issues. If you're having these symptoms, I'd recommend getting it checked soon.

Thanks so much for sharing your experience! That's really helpful to know it was just the auxiliary battery, sounds exactly like what I'm dealing with. I've been worried it might be something more serious. Would you mind sharing what the repair cost you? And has everything been running smoothly since the fix, or have you noticed any other issues pop up? Really appreciate your help with this!

Hey again! Happy to report that since getting the auxiliary battery replaced, my i3s has been running like a dream! The repair cost me 290 € total, which included the new battery, programming, and labor. Honestly, it was worth every penny, no more unusual warning lights or starting issues since then. The mechanics did a great job sorting it out, and the battery malfunction warning hasn't appeared once since the fix. The start-stop system is working perfectly now, and all the electrical systems are functioning just as they should. It's such a relief not having to worry about whether the car will start properly every morning! Just make sure they use the right battery spec and properly code it to your i8's system, that's crucial for these hybrid BMWs. Trust me, getting it sorted sooner rather than later is definitely the way to go. Feel free to ask if you need any other details about the repair!

Thanks again for all the info! Just wanted to update, I took your advice and got it sorted yesterday. The mechanic confirmed it was indeed the auxiliary battery, just like you said. I actually ended up paying a bit more than you did, around 350 €, but honestly, I'm not even mad about it. They did a thorough job and even showed me what was wrong with the old battery. The best part? My i8 is running perfectly now! No more heart-stopping moments wondering if it'll start, and all those annoying warning lights are gone. The start-stop system is working like new again. The mechanic mentioned I caught it at a good time before it could cause any other issues. Really grateful for your help, saved me from stressing out over what could've been a much bigger problem. Sometimes the simplest solution is the right one, right? Catch you around!