BMW i8 Power Seat Controls Dead, Electrical Issue Help

Hey there! I had a similar electrical issue with my 2015 BMW i3. The symptoms you're describing sound exactly like what I experienced. The root cause in my case was a failing battery cell in the 12V auxiliary battery, not the main hybrid battery. When I took it to the garage, they ran diagnostics and found the 12V battery wasn't holding charge properly, causing various electrical components to malfunction, including the power seats. The battery was heavily discharged and couldn't maintain proper voltage for the seat motors and memory functions. It was a pretty straightforward fix once they identified the actual problem. They replaced the 12V battery and recalibrated the electrical system. Not a serious issue, but definitely something that needs proper attention since it can affect other electrical components if left unchecked. If you're seeing similar symptoms, I'd recommend getting the 12V battery checked first before looking into more complex electrical issues. The seat memory quirks are often a good indicator of low voltage problems. Hope this helps with your decision.

Hey, thanks for sharing your experience! That's really helpful info about the 12V battery being the culprit. I might try checking that first before diving into anything more complicated. Would you mind sharing what the battery replacement and recalibration ended up costing you? Also curious if you've had any other electrical problems since getting it fixed? Been a bit wary of mechanics lately, so trying to get a good idea of what I'm walking into.

Hey again! Thanks for asking about the follow-up. Actually, I can give you some good news about my repair experience. The total bill came to 290 € for the battery replacement and system recalibration. But here's the best part, it completely solved both the battery issue and the passenger seat electrical problem that was driving me nuts! Since that repair job a few months back, the car's been running like a dream. No more electrical gremlins popping up, and all the power functions work exactly as they should. The seat memory settings kick in right away now, just like they're supposed to. I totally get being cautious about mechanics, I was too after some dodgy experiences. But I've got to say, this repair was worth every penny. The diagnostic they ran really pinpointed the exact issue, and they sorted it properly the first time around. If your symptoms are matching what I had, you're probably looking at a similar fix and cost. Much better than having to deal with more complex electrical issues, right? Let me know if you end up getting it sorted, would be interested to hear if you had the same root cause!

Thanks for all that detail! Just got back from the mechanic actually. You were spot on about the 12V battery! Took it to a different shop this time, and what a difference. The guy actually showed me how the old battery was barely holding charge. The fix was pretty much identical to yours, new battery and system reset. Mine came in slightly higher at 340 € but honestly, I'm just relieved it wasn't something major. Money well spent considering everything's working perfectly now. The seat adjustments are responding instantly, and all the memory settings are back to normal. Funny how something as simple as a battery can cause such weird problems! Really appreciate you sharing your experience, saved me from stressing about potential bigger issues. The mechanic I found was great too, super transparent about everything. Think I've finally found a reliable place for future service. Thanks again for pointing me in the right direction!