Self-discharge rate evaluation method for battery cell

Abstract

The invention discloses a self-discharge rate evaluation method for a battery cell. The self-discharge rate evaluation method includes the following steps: 1, collecting usage data of the battery cellin the past period of time, and extracting current data and SOC data to learn discharge currents and changes of remaining capacity of the battery cell in the past period of time; 2, calculating the electric quantity outputted by the battery cell in the past period of time according to the discharge currents; 3, calculating the total electric quantity consumed by the battery cell in the past period of time according to changes of the SOC data; 4, calculating a difference value between the output electric quantity and the consumed total electric quantity of the battery cell, acquiring the electric quantity consumed by self-discharge of the battery cell in the past period of time, and further acquiring the electric quantity consumed by self-discharge of the battery cell in unit time, namelythe average self-discharge rate of the battery cell in the past period of time; 5, continuously recording and storing the average self-discharge rate of the battery cell in several time periods, and evaluating the self-discharge rate of the battery cell according to historical data and standard data.

Description

Technical field [0001] The invention relates to the technical field of automobile battery detection, in particular to a method for obtaining real-time operating data of the battery during use of the battery for evaluating its self-discharge rate. Background technique [0002] The raw materials used for battery production are inevitably mixed with impurities and cannot be 100% pure. Therefore, the battery produced will have self-discharge. The self-discharge rate of different types of batteries is different, and the self-discharge rate of the same battery in different time periods is also different, usually in the range of 10-35 %. Self-discharge will increase the internal resistance of the battery, reduce the load capacity of the battery, and reduce the capacity of the battery cell, which in turn affects the consistency and service life of the battery pack. [0003] As the power source, the battery pack is one of the most important parts of electric vehicles. In order to detect t...

AI Technical Summary

Problems solved by technology

In order to detect the use of the battery pack, it has become a routine setting to equip it with a battery management system, but the existing battery management system does not have the function of evaluating the self-discharge rate of the battery cell

[0004] In the existing technology, the battery self-discharge rate data is obtained mainly by measuring the capacity change of the battery cell when it is left standing for a long time (open circuit), which can only be carried out in 4S shops or professional repair shops, and there is no way to obtain the battery self-discharge rate in time. Information and problems that affect the normal use of the battery during the measurement period, affecting the service life of the battery pack

Images