Method and system for evaluating battery monomer consistency

Abstract

The embodiment of the invention discloses a method for evaluating the battery monomer consistency. The method comprises the following steps: acquiring and recording the temperature, the current, and the remaining battery capacity of the battery system at each shard moment in the total time and the voltage value of each monomer through a battery management system; calculating the monomer voltage difference according to the voltage value of each monomer and counting the total quantity of the monomer voltage differences within the range of the same temperature, remaining battery capacity and current section and the proportion of the quantity of each monomer voltage difference in the total quantity; evaluating the monomer consistency according to the proportion, wherein when the proportion of the quantity of each monomer voltage difference exceeding a predefined threshold value in the same current section in the total quantity is higher, the monomer consistency is shown to be worse. The embodiment of the invention further discloses a system for evaluating the battery monomer consistency. The embodiment of the invention solves the problem in the prior art that the battery monomer consistency under the static condition before and after the assembly of the battery system only can be evaluated, and the battery monomer consistency in a use state after assembly cannot be evaluated.

Description

technical field [0001] The invention relates to the technical field of battery management, in particular to a method and system for evaluating the consistency of battery cells. Background technique [0002] New energy vehicle batteries are composed of multiple battery cells connected in series and parallel, so the requirements for the consistency of the battery cells are very high, and the consistency of the battery cells is usually determined by the battery manufacturer before leaving the factory. The AC internal resistance, capacity and open circuit voltage are tested, and the consistency of the battery monomer is evaluated according to the AC internal resistance, capacity and open circuit voltage obtained by the test, and then by selecting the AC internal resistance, capacity and open circuit voltage. The battery cells form the battery system. The disadvantage of this method is that it can only evaluate the consistency of the battery cells before they are assembled into ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the embodiments of the present invention is to provide a method and system for evaluating the consistency of battery cells, which can solve the problem of evaluating battery cells under static conditions before and after being assembled into a battery system in the prior art. Consistency, but it is impossible to evaluate the consistency of battery cells in use after they are assembled into a battery system

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