Comparative analysis of battery protection board and battery management system BMS

2021-09-02 08:44:31 0

Do you know the difference between the battery protection board and the battery management system BMS? With the global diversification, our lives are constantly changing, including the various electronic products we come into contact with, so you must not understand these products Some components, such as battery protection board and battery management system BMS.

BMS, and the full English name is Battery Management System. The function of the battery management system is to protect the safe use of the battery pack. In the process of charging and discharging the battery pack, while ensuring safety, the service life of the battery pack can be prolonged. In many electronic devices that require battery power, the usage of rechargeable batteries has increased dramatically. To ensure that the battery is properly charged and to optimize its service life, the battery management or fuel gauge system will rise in parallel. The BMS battery management system is now complete. The lithium-ion battery protection board also has a balanced protection purpose, and there are two ways of energy consumption and energy transfer. Energy balance refers to the use of resistors to consume a certain battery with high power or high voltage in multiple battery strings. Energy consumption balance is divided into balance during charging, fixed-point voltage balance and static automatic balance. The reason why lithium-ion batteries (rechargeable) need to be protected depends on their own characteristics. Because the material of the lithium-ion battery itself cannot be overcharged, over-discharged, over-current, short-circuited, and ultra-high temperature charging and discharging, the lithium-ion battery components of the lithium-ion battery will always have an exquisite protection board and current fuse.

Battery Management System is abbreviated as BMS, which has the function of measuring battery voltage, and also includes battery protection function, battery equalization function, battery reserve function, energy calculation function, network communication function, etc. The battery management system can prevent the battery from over-discharge, over-charge, over-temperature and other abnormal conditions.

The protection function of lithium-ion battery is usually completed by the protection circuit board and current devices such as pTC. The protection board is composed of electronic circuits, which can accurately monitor the voltage and charge and discharge circuit of the cell at all times under the environment of -40℃ to +85℃ It can control the on-off of the current loop in time; pTC prevents severe damage to the battery in a high temperature environment.

Lithium-ion battery protection board is composed of IC, MOS tube, resistor and capacitor, and is an important part of lithium-ion battery. The battery management system can be edited and has its own battery management software, which is relatively smarter and is equivalent to the brain of a lithium-ion battery for control. One of the key functions of the BMS battery management system is to manage the battery system to ensure that it will not be overcharged, or that its charging will not drop to the stage where it is necessary to shut down the running equipment because the power is exhausted without warning. The battery management system should supply warnings so that the equipment can be shut down in an orderly manner. The environmental management part of the battery management system will determine when to charge the battery and how much power it receives. Since the lifespan of batteries such as lithium-ion batteries and other batteries depends to a large extent on the number of charge/discharge cycles, many battery management systems charge the battery only when necessary. Regarding the lithium-ion battery protection board, when the battery is discharged to an external load, its voltage will gradually decrease with the discharge process. When the battery voltage drops to 2.5V, its power has been completely exhausted. At this time, if the battery continues to discharge, the load will cause permanent damage to the battery. During the battery discharge process, when the control IC detects that the battery voltage is lower than 2.3V (this value is determined by the control IC, different ICs have different values), its "DO" pin will change from high voltage to zero voltage, so that T2 cuts off the discharge circuit from on to off, so that the battery no longer discharges to the load, and plays the role of over-discharge protection. At this time, due to the presence of the body diode VD2 of T2, the charger can charge the battery through this diode.