BMW iX2 Battery System Failures & Starting Issues

Hey there, fellow BMW owner. I had nearly identical issues with my 2021 BMW i4 last winter. The symptoms you're describing match exactly what I experienced, dim lights, multiple system warnings, and startup problems. Turned out my 12V auxiliary battery was completely shot, not the main EV battery. These auxiliary batteries support all the electronics and basic functions, and when they fail, it causes havoc with all systems. This happened to me at around 125,000 km. My experience wasn't a quick fix, had to wait for the battery since it's a specific type for EVs. The voltage regulator also needed replacement as it had been affected by the failing battery. Not a cheap repair but definitely critical to get sorted out. Would strongly suggest finding another certified EV mechanic for a second opinion. With those symptoms, you really want someone who knows BMW electric systems well. In my case, delaying the repair led to more electrical issues.

Thanks for sharing your experience! It's really helpful to know that it was the 12V battery in your case. I'll definitely look into finding a certified EV specialist for a proper diagnosis. Just curious, do you remember roughly how much you ended up paying for the whole repair? Also, have you had any other electrical issues pop up since getting it fixed? My BMW iX2 is my daily driver, so I want to make sure I get it sorted properly the first time.

Hey again! Glad I could help! Just wanted to follow up, I actually just got my i4 back from the shop last week after dealing with that undervoltage issue. Good news: everything's working perfectly now. They fixed the heavily discharged battery and the car is running like new again. The total bill came to 290 € for the battery replacement and labor. Money well spent, if you ask me. Since the repair, all those annoying electrical problems have completely disappeared, no more flickering lights, no more system warnings, nothing. The car starts up instantly every time. I'd definitely recommend getting yours checked out by a certified EV specialist asap. These 12V battery issues can cause a real headache if left too long. For what it's worth, I haven't had a single electrical problem since the fix. My i4 is also my daily driver, so I totally get wanting to sort it out properly the first time around. Quick tip: once you get it fixed, they recommended starting the car at least once every few days, even if you're not using it, to keep the 12V battery in good shape. Been doing that religiously since the repair.

Thanks everyone for the help! Just wanted to update you on my BMW iX2 situation. Finally got around to taking it to a new mechanic, a certified EV specialist this time. You were spot on about the 12V battery being the culprit! The experience was way better than my last mechanic visit. The specialist knew exactly what to look for and found that both the auxiliary battery and voltage regulator needed replacement. The repair took a couple of days because they had to order the specific battery type, but it was worth the wait. The final bill came to around 350 due to both parts needing replacement, but honestly, I'm just relieved to have it sorted. Car's running perfectly now, no more flickering lights, system warnings are gone, and it starts up instantly. They gave me the same advice about regular starts to maintain battery health, which I'm definitely following. Really appreciate all the input from everyone. Saved me a lot of headache and probably some money too by pointing me in the right direction! Time to enjoy my properly functioning BMW again.