The term Battery Monitoring (or Management) System is used in at least two different ways regarding LiFePO4 battery banks:
cell-level monitoring and cutoff for overvoltage or undervoltage; these are intended to maintain balance between cells of fast, high-current charging, as found in electric vehicles (EVs).
bank-level monitoring and High Voltage Disconnect and Low Voltage Disconnect.1)
In an an RV these would be acommplished by the charge controller and an LVD respectively. This simple approach is advocated by T1 Terry, who believes the cell-level BMS is an unneeded expense for Fractional C charging and can do damage by poor design2)