mcristiani wrote:If the BMS says 2.5v as the lvc, what is controlling the cutoff though?
The BMS's electronics are setup for a particular voltage usually for a particular chemistry.
If you use a BMS that runs down to 2.5v on cells that are empty at voltages higher than that, and you use the battery until the BMS shuts off, then you are destroying the cells by running them down too low. The damage may be slow, or it may be quick, depending on the particular cell characteristics and chemistry, but it is happening.
So you should change that BMS to one with an LVC that is for the correct chemistry of the cells.
The one you have now is not made for those cells, it is made for a different chemistry, probably LiFePO4, as has already been pointed out above. It should not be used with the non-LiFePO4 cells you have.