About the method of equalizing charging of the protection board of the lithium battery pack

　　Power lithium batteries are used in groups. Each lithium battery requires protection of over-voltage, under-voltage, over-current, and short-circuit protection. During the charging process, the problem of balancing the entire group of batteries is introduced. A single-cell lithium battery is introduced. A design scheme of a battery pack protection board with equalizing charging function that protects any number of groups of lithium batteries connected in series with the protection chip.

　　Power lithium batteries are used in groups. Each lithium battery requires protection of over-voltage, under-voltage, over-current, and short-circuit protection. During the charging process, the problem of balancing the entire group of batteries is introduced. A single-cell lithium battery is introduced. A design scheme of a battery pack protection board with equalizing charging function that protects any number of groups of lithium batteries connected in series with the protection chip. Simulation results and industrial production applications prove that the protection board has complete protection functions, stable operation, high cost performance, and equalization charging error less than 50mV.

　　Commonly used equalization charging techniques include constant shunt resistance equalization charging, on-off shunt resistance equalization charging, average battery voltage equalization charging, switched capacitor equalization charging, step-down converter equalization charging, inductance equalization charging, etc. When charging a group of lithium batteries in series, ensure that each battery is charged in a balanced manner, otherwise the performance and life of the entire group of batteries will be affected during use. However, the existing single-cell lithium battery protection chips do not have a balanced charge control function. The balanced charge control function of a multi-cell lithium battery protection chip requires an external CPU; it is realized through serial communication with the protection chip (such as I2C bus). The complexity and design difficulty of the protection circuit are reduced, the efficiency and reliability of the system are reduced, and the power consumption is increased.

　　Power lithium batteries are used in groups. Each lithium battery requires protection of over-voltage, under-voltage, over-current, and short-circuit protection. During the charging process, the problem of balancing the entire group of batteries is introduced. A single-cell lithium battery is introduced. A design scheme of a battery pack protection board with equalizing charging function that protects any number of groups of lithium batteries connected in series with the protection chip. Simulation results and industrial production applications prove that the protection board has complete protection functions, stable operation, high cost performance, and equalization charging error less than 50mV.

　　Lithium battery pack protection board balanced charging principle structure

　　The number of single-cell lithium battery protection chips is determined according to the number of lithium battery cells, and they are used in series to protect the corresponding single-cell lithium battery from charging and discharging, overcurrent, and short-circuit conditions. While charging and protecting, the system realizes balanced charging by controlling the on and off of the shunt discharge branch switch device through the protection chip. This solution is different from the traditional method of realizing balanced charging on the charger side, and reduces the design of the lithium battery pack charger. The cost of the application.