Method for measuring electric quantity of lithium ion batteries and its device

Abstract

First, the method obtains the group of relation curves and fitting functions between the surplus energy and the open circuit voltage in the service time of lithium ion batteries. Based on the modified module value of the low frequency alternating current impedance, the one of the said curve or fitting function is selected. Based on the open circuit voltage and the selected fitting function, the surplus energy of the battery is calculated out. The device includes the cast and the internal circuit boards composed of interconnection of the microcomputer, the circuit for controlling the charge current, the amplification circuit for charging and discharging current signal, the current measurement circuit and thue pure oscillator etc.

Description

(1) Technical field

[0001] The invention relates to the technical field of lithium battery power measurement, in particular to a method and a device for measuring the power of a lithium ion battery. (2) Background technology

[0002] The measurement of the remaining power of the lithium battery is generally used at present by the product method and the voltage method. The product algorithm is to continuously detect the discharge current and discharge time of the battery at each moment to accumulate the discharge power of the battery. Then subtract the accumulated discharge capacity from the fully charged capacity of the battery (usually the nominal capacity of a new battery) to obtain the remaining capacity. The disadvantage of the integration method is that it needs to memorize and store the electricity consumption history of the battery during the discharge cycle in order to accumulate the total discharge capacity. However, as the number of battery charging and dischargi...

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