Hi all, I am a beginner in electric transport. The question is a few months ago I bought a used chinese electric scooter. Is a 5Kw, motor is in rear wheel, 72V/40Ah Thunder sky batteries (24 cells) with BMS cell by cell.
Until last week everything was perfect, the scooter have 3000kms and I can ride 70kms per charge at 85kms/h.
The problem is now range is 35kms per charge. I have tested voltage cell by cell and one of them is 0 and cell is swollen. When scooter stops voltage cell by cell is 2,6V, When scooter is full charged voltage cell by cell is 3,5/3,6 except damaged cell with 0 volts.
The question is how is this possible if I have a BMS?, maybe it does not work? How can I know if BMS is working or not?