Monitoring system for electric quantity of lithium battery

Abstract

The invention relates to a monitoring system for the electric quantity of a lithium battery. The monitoring system comprises a state monitoring unit, an electric quantity recording unit, an impedance tracking unit, an arithmetic element and the lithium battery, wherein the state monitoring state monitors the current output voltage, the output current and the ambient temperature of the lithium battery; the electric quantity recording unit records the input electric quantity during the charging of the lithium battery and the output electric quantity during the discharging of the lithium battery; the impedance tracking unit calculates the internal impedance of the lithium battery after the charging of the lithium battery is completed every time; the arithmetic element calculates the remaining electric quantity and the remaining working hour of the lithium battery according to input data; the system monitors the whole charging / discharging process of the lithium battery, takes a complete charging and discharging time as a period, dynamically updates battery capacity based on an integral method and eliminates the influence of the variation of the battery capacity; after the battery is fully charged every time, the impedance tracking unit of the lithium battery is started so as to update the internal resistor of the lithium battery; finally, the remaining electrical quantity and the remaining working time of the lithium battery are calculated by combining the environment temperature, the loading and the like.

Description

technical field [0001] The invention relates to a lithium battery power monitoring system, which can accurately measure the remaining power of the battery and accurately estimate the remaining working time of the battery. Background technique [0002] Lithium batteries have been widely used in portable devices due to their excellent characteristics such as high energy and no memory. With the increasing requirements of portable devices for accurate indication of battery power and accurate estimation of remaining working time, the existing lithium battery power monitoring system is increasingly unable to meet the needs of users. [0003] The existing battery power monitoring system mainly uses the voltage monitoring method and the coulomb counting method, and its main disadvantages are: [0004] 1. The voltage monitoring method combines the current battery voltage and the normal temperature discharge curve to determine the remaining battery power. Since the voltage monitorin...

AI Technical Summary

Problems solved by technology

[0006] As the battery age increases, the capacity of the battery will decrease and the impedance of the battery will increase, which will lead to a decrease in battery runtime

Since neither the voltage monitoring method nor the coulomb counting method can solve the above problems, the battery power monitoring system designed using the voltage detection method and the coulomb counting method must reserve energy in order to prevent sudden shutdown, which will cause a waste of electric energy

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