Charging apparatus and method for lithium ion battery pile

Abstract

The invention discloses a charging device and a charging method for lithium ion battery packs. The charging device comprises an alternating current power supply, a switch power supply, a current detection circuit, a voltage detection device, an electronic switch or an OR-gate circuit. The alternating current power supply carries out rectifying and filtering to an alternating current input power supply, the switch power supply is utilized to modulate the input current and the voltage of the charging device, the current detection circuit and the voltage detection device detect the output current and the output voltage of the charging device, the electronic switch is utilized to switch the signals fed back by the voltage detection device, and the OR-gate circuit is utilized to select feedback signals of the current detection circuit and the voltage detection device. During charging, a battery pack internal management system outputs a reference voltage of charging current value and determines the state of the battery pack, thereby outputting a charging control signal for performing constant-current charge. When the condition of constant-voltage charge is reached, a constant-voltage charging interference voltage and a control signal are output to carry out constant-voltage charge. The charging is terminated when the charging current is less than 1 / 20 of capacity of the battery pack. By utilizing the charging device and the charging method for lithium ion battery packs, the performance of the lithium ion battery pack can be improved, and the complexity and the cost of the management system can be reduced.

Description

technical field [0001] The invention relates to battery charging technology, in particular to a charging device and a charging method for a lithium-ion battery pack, Background technique [0002] Lithium-ion power battery packs are used more and more widely. The existing charging control system for lithium-ion battery packs uses a constant current and then constant voltage charging method to charge the battery pack with a fixed current and voltage. However, when the consistency of the battery pack changes, due to the accuracy of the voltage control, the voltage of the single battery must be higher than the set end-of-charge voltage of 4.2V. If 42V constant voltage charging is used for constant voltage charging of 10-string lithium-ion battery packs, the charging voltage of some single cells will be higher than 4.2V, which will lead to rapid attenuation of battery pack performance. During the charging process, if it cannot be controlled in time, it is easy to cause safety pr...

AI Technical Summary

Problems solved by technology

For example, 42V constant voltage charging is used for constant voltage charging of 10 series lithium-ion battery packs, and the charging voltage of some single cells will be higher than 4.2V, which will lead to rapid degradation of battery pack performance.

During the charging process, if it cannot be controlled in time, it is easy to cause safety problems

[0003] Although this effect can be reduced by balancing the control circuit, it increases the size and cost of the charging control system

The existing fixed-value charging control system increases the possibility of overcharging of single cells in lithium-ion battery packs, which places high demands on the management system of lithium-ion battery packs

Moreover, the performance parameters of the lithium-ion battery pack have changed at the end of the cycle, and this fixed charging method will no longer be suitable for the lithium-ion battery pack, which will lead to a rapid decline in the performance of the battery pack.

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