My 2015 BMW i3 was flawless until I reached the 100,000 mile mark and my 12v battery failed. Since then the root of all issues has to do with my 12v battery. I read this forum as well as visited You Tube for how to replace the battery. First error was not waiting 30 minutes to allow the computer to reset after installing the new Remy 12v and reconnecting the HV Battery. Later my i3 shut down completely after hitting a bump in the road. I had the flickering dashboard, drive train error message and ultimately a black screen. I had loose 12 v battery terminals and the new battery discharged. It was pulled, recharged, load tested and reinstalled. I am at 111,000 miles now. I commute with my i3 car 70 miles a day.