A Battery Management System (BMS) is arguably the most important piece of a smart battery. It protects the battery from outside forces that can damage the internal cells.
If the battery short circuits for example, the BMS can detect this and shutoff for a predetermined amount of time.
Lithium Iron Phophate batteries are sensitive to extreme temperatures, so there are temperature probes connected to the BMS, and predefined settings determine when the battery should shutoff to protect itself.
There are also over/under voltage protections that will prevent discharging the LiFePO4 batteries to deeply or overcharging to dangerous levels.
Think of the BMS as a micro-computer that’s running 24/7 protecting itself and your investment.