Calibration method of charge and discharge characteristics of lithium battery and charge and discharge characteristics calibration apparatus

Abstract

The invention discloses a calibration method of charge and discharge characteristics of a lithium battery. The calibration method includes 1, subjecting a lithium battery to be tested to constant-current charging and finishing the charging once the battery voltage reaches to the rated maximum voltage; calculating battery level after charging, in the formula, t1 is the charging time, i is charging current, and Eta is battery efficiency coefficient, to be specific, the Eta=EtaT*Etat*Etai, EtaT is temperature influence coefficient, Etat is aging coefficient, and Etai is charge and discharge multiplying factor coefficient; subjecting the lithium battery to be tested to discharging and finishing the discharging once the real-time voltage reaches to the rated minimum voltage; calculating the maximum charging capacity Q2, in the formula, i is discharging current, t2 is discharging time, and Eta is battery efficiency coefficient; according to Q1 and Q2, calibrating the initial charging state of the battery and drawing function curve of the charging voltage-SOC. The calibration method is available in a charge and discharge characteristics calibration apparatus, accurate to calculate and wide in application range. The charge and discharge characteristics calibration apparatus is simple in circuit, light and small and easy to operate.

Description

technical field [0001] The invention specifically relates to a calibration method for charging and discharging characteristics of a lithium battery and a charging and discharging characteristics calibrating instrument used for implementing the method, belonging to the field of lithium battery measurement. Background technique [0002] Compared with ordinary lithium batteries, lithium iron phosphate batteries have the advantages of high voltage, strong over-discharge capability, long cycle life, good safety performance, less self-discharge, and fast charging. Lithium iron phosphate batteries are more and more used in Electric vehicles, electric tools, toys, portable medical equipment, warning lights and other mobile devices. [0003] In order to protect mobile devices and prolong battery life, it is usually necessary to establish a battery management system to manage lithium iron phosphate batteries. The establishment of the battery management system needs to accurately esti...

AI Technical Summary

Problems solved by technology

However, this method lacks the judgment of the aging state of the battery. It is considered that the maximum charging capacity of the battery is the rated power, and the battery that has been placed for a long time or used in an extreme environment usually has a maximum charging capacity that cannot reach the rated power. The SOC measured by the battery has a large error, which lacks reference value for the establishment of the battery management system

Moreover, this method only detects the state of charge, and cannot provide a voltage-SOC curve, and the information on the charging and discharging characteristics of the battery is not comprehensive.

In addition, the volumetric instrument used in this method is large in size and difficult to share with environmental equipment such as incubators, and there is no treatment method for measurement errors caused by ambient temperature

Images