A battery management system is essentially the “brain” of a battery pack; it measures and reports crucial information for the operation of the battery and also also protects the battery from damage in a wide range of operating conditions. The single most important function that a battery management system performs is cell protection. Lithium ion battery cells have two critical design issues; if you overcharge them you can damage them and cause overheating and even explosion or flame so it's important to have a battery management system to provide overvoltage protection . Lithium ion cells can also be damaged if they're discharged below a certain threshold, approximately 5 percent of total capacity. If the cells are discharged below this threshold their capacity can become permanently reduced. To ensure a battery's charge doesn't go above or below its limits, a battery management system has a safeguard device called a dedicated Lithium-ion protector Every battery protection circuit has two electronic switches called "MOSFETs." MOSFETs are semiconductors used to switch electronic signals on or off in a circuit. A battery management system typically has a Discharge MOSFET and a Charge MOSFET. If the protector detects that the voltage across the cells exceeds a certain limit, it will discontinue the charge by opening the Charge MOSFET chip. Once the charge has gone back down to a safe level then the switch will close again. Similarly, when a cell drains to a certain voltage, the protector will cut off the discharge by opening the Discharge MOSFET. The second most important function performed by a battery management system is energy management. A good example of energy management is your laptop battery's power meter. Most laptops today are not only able to tell you how much charge is left in the battery but also what your rate ...
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