Fyi, as individual cells charge or discharge you could have a cell that could go rogue. The bms for over voltage in 3 tons case is 3.9 vpc which should shut the the charging down or turn the battery off depending on how it's setup. The passive balancing should take care of this but incase there is a runner one cell could get there, the likely hood of all cells doing it is very unlikely.
This is why you need to have properly setup charging system that stops charging first and the battery bms is the last line of defense.
3 tons does your battery shut down completely if there cell over voltage or cell under voltage event or does it just disconnect the charging or discharging?