Lithium ion battery pack state-of-health evaluation method and lithium ion battery pack state-of-health evaluation system

Abstract

The invention discloses a lithium ion battery pack state-of-health evaluation method and a lithium ion battery pack state-of-health evaluation system. According to the method, first, the state of health of a battery pack is preliminarily judged according to the end voltage of each battery string in the battery pack, and then, the state of health of the battery pack is comprehensively evaluated from the discharge capacity, internal resistance and temperature of the battery pack. The system comprises a control unit, a battery charging and discharging unit, a protection unit and a sound-light-electricity display unit. The control unit comprises a data reading unit, a data storing unit, a data processing unit and a data sending unit. According to the evaluation method and the evaluation system provided by the invention, all kinds of complicated environmental influences facing the battery pack in the using process are considered, comprehensive evaluation of the state of health of the batteries in the battery pack is completed, and the accuracy of test results is improved.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a method and system for evaluating the health state of a lithium-ion battery pack. Background technique [0002] The world's oil crisis and environmental pollution are becoming more and more serious. Countries are calling for environmental improvement and energy conservation. Mandatory indicators such as emissions from traditional vehicles have been tightened year by year. Compared with traditional vehicles powered by internal combustion engines, electric vehicles use battery packs as energy storage power sources to drive motors to drive vehicles. Electric vehicles are the future development direction of new energy vehicles, and power batteries are the core of electric vehicles. Lithium-ion batteries have the characteristics of high working voltage, high energy density, light weight, small size, low self-discharge rate, long cycle life, no memory effect, and environmental frie...

AI Technical Summary

Problems solved by technology

However, there are great differences between batteries before and after grouping, and the problems in group application are more complicated and prominent than those of single cells. The impact makes the specific energy, specific power and other performance parameters of the battery pack often not reach the original level of the monomer, and what is more serious is that the service life is significantly shorter than that of the single battery. The reason is that the health of the battery pack is determined by the string / The health status of each single battery connected in parallel is determined. When the health status of one or some batteries deteriorates sharply, the health status of the entire battery pack will also be affected.

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