I am trying to build a 2s 7.4V solar charged lithium battery pack to power an arduino UNO and SIM900 GSM shield. I have a 12V, 10W solar panel, BMS protection board and a DC-DC CC CV buck converter like the one in the link below. Now I know that I can use the CC CV converter to control the output voltage (7.4V) and current to the battery.
Question: Is it necessary to use a BMS protection board to stop current flow to the battery once the battery is fully charged i.e. reaches the output voltage of the converter? Does a BMS protection board cut the current supply to the battery completely?
Please help me in understanding the a battery charge controler vs combination of DC-DC CC CV converter and BMS protection board.