Battery control lamp flickers LiMa and battery new

Moin! My Arosa first started flickering with the LKL, then the LiMa was changed. Lamp flickered further. New battery problem Was gone! After about 2-3 weeks it is now completely escalated. I was just on my way home when suddenly the on-board electronics failed, then only 8,7V were available. Just saved to home and now I stand there and don’t know. Are the coals through after 3 weeks? / Battery after 4 days capped? LiMa from 70AH charging current to 90AH Improved. Battery from 44AH to 65AH Improved. Vehicle: Seat Arosa 6hs BJ: 2004 50 Ps // 1.0MPI Vehicle has a Hi-Fi system that naturally also causes the on-board voltage to fluctuate, which has not caused any problems before. Range 0.1V – 0.5V