60V battery only charges to 63.5V instead of 67.5V

[CrossRoads]

I have multiple 60V batteries and have tested the charger on the other battery, which charges up to the expected 67.4 / 67.5 just fine, so i know the issue is with the battery, not the charger. Just wondering what this could be indicative of. A problem with the BMS? unbalanced cells?

 

[HumanPerson]

could be BMS could be bad cells could be bad cell group...