Hello, I have purchased a 2017 Octavia MK3 1.6TDI. Right from the start the car displayed a "Low 12v battery, start the car in order to use the infotainment" error. I did that, I got a Varta AGM 70Ah 760ah and coded using a friend's VCDS. I was away for work and used the car about 1 time a week with no errors (I even did a 200km trip, no problem). As I changed job i started using it more often and it started telling me the error above. With a multimeter I checked and the error appeared even with the battery at 12.4v or 12.76v before turning it on. It's not an alternator problem as it charges (12.9v-13.3v-13.4v). I even removed the negative to see if the car stayed on and it did. The previous owner mounted canbus LEDs in the foot area, above the head and in the trunk. But those should not be a problem. Has anyone encountered a similar problem? Is there a firmware update that I can do? (does the BCM need one? i dont know).