Lithium battery pack charging method

Abstract

The invention provides a lithium battery pack charging method. According to the lithium battery pack charging method, the diversity of single cells is gradually reduced by adopting four stages of a constant-current pre-charging mode, a constant-current equalizing charging mode, a constant-voltage current-reducing charging mode, and a constant-current trickle charging mode. The relatively poor single cell can be relatively fully charged, and the relatively good cell can be discharged in an equalizing manner by controlling the charging time and charging current of the single cell with a relatively poor performance so as to achieve the effect that the diversity of the single cells is well reduced. The cells can be recovered to a certain degree by stopping charging for a period of time in the constant voltage charging mode, the voltage of the relatively-high-voltage single cell is reduced to a certain degree, so that the charging time can be prolonged for the relatively low voltage cell, and finally the cell is charged with trickle with the minimum charging current. This period of the charging time is prolonged so that the relatively low voltage cell keeps to be changed for a long time. In the whole charging process, the diversity of the single cells is reduced by prolonging the charging time so as to achieve the effect that the cells are relatively fully charged, and the service life of a battery pack is relatively long.

Description

Technical field [0001] The invention relates to a battery charging method, in particular to a lithium battery pack charging method. Background technique [0002] The current battery charging mode, especially the charging mode for lithium batteries, mainly uses constant current and constant voltage charging modes to charge the battery successively. Although this charging method takes into account the basic characteristics of the battery, it guarantees the lithium battery to a certain extent It can be fully charged before the life cycle, which is more suitable for battery packs composed of a single or a few batteries, but the battery packs currently used in the electric vehicle industry are multiple single cells combined in series, and the characteristics of each single cell Different, with the use of the battery, the environment of the battery cell is different, especially in the middle and late stages of the battery pack life. Such a simple constant current and constant voltage ...

AI Technical Summary

Problems solved by technology

[0002] The current battery charging mode, especially the charging mode for lithium batteries, mainly uses constant current and constant voltage charging modes to charge the battery successively. Although this charging method takes into account the basic characteristics of the battery, it guarantees the lithium battery to a certain extent. It can be fully charged before the life cycle, and it is more suitable for a battery pack composed of a single or a few batteries. However, the battery packs currently used in the electric vehicle industry are combined in series with multiple single cells. The characteristics of each single cell They are all different. With the use of the battery, the environment of the battery cells is also different, especially in the middle and late stages of the life of the battery pack. Such a simple constant current and constant voltage mode charging method will lead to the inconsistency of the battery cells. It is getting bigger and bigger, the high-voltage monomer reaches the charging stop first, and the low-voltage battery has not reached it, and finally the entire battery pack is always in a state of not being fully charged, which seriously shortens the life of the battery pack

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