Lithium-ion battery pack balancing method and system

Abstract

The invention discloses a lithium-ion battery pack balancing method and system. The lithium-ion battery pack balancing method is mainly used for converting single battery bodies into a serial-connected state when a battery pack needs to be charged or discharged, and converting the single battery bodies into a parallel-connected state when the battery pack needs to be balanced. The lithium-ion battery pack balancing system comprises the battery pack and a serial-to-parallel converting device, wherein both electrodes of each single battery body are respectively led out by lead wires; the serial-to-parallel converting device comprises wiring terminals, a connection mechanism and a converting mechanism; the lead wires of the both electrodes of each single battery body are respectively connected with the wiring terminals; and the converting mechanism controls the connection mechanism or the wiring terminals to move, so that connection relation between the wiring terminals can be converted, and the single battery bodies are connected in series or in parallel. With the adoption of the serial-to-parallel converting method provided by the invention, the advantages of simple structure, low cost, no energy consumption, manul control and low failure probability can be realized; and the problems that the other balancing methods have the defects of complex structure, high cost, instability of electronic control and low energy utilization rate can be solved.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a balancing method and system for a lithium-ion battery pack. Background technique [0002] Since the discharge voltage of lithium-ion batteries is between 2.5 and 4.2V, it cannot meet the needs of high-voltage electrical appliances, and usually requires multiple sets of batteries to be used in series. However, since lithium-ion batteries involve issues such as technology, process control, and use environment, there are differences in self-discharge between cells. 1 / C,C 1 is the charging capacity of the battery at that time, and C is the actual capacity of the battery) there is a serious inconsistency, which leads to a rapid decline in the capacity of the battery pack and a reduction in the service life. Therefore, the lithium-ion battery pack needs to be equipped with a balancing module to balance the SOC of each battery, improve the capacity and per...

AI Technical Summary

Problems solved by technology

This method has obvious disadvantages: the secondary winding of the transformer is difficult to match, the voltage difference caused by the leakage inductance is difficult to compensate, it is not easy to be modularized, and the internal voltage of the switch tube is high, etc.

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