Single storage-battery internal resistance measuring circuit and method

Abstract

The invention provides a single storage-battery internal resistance measuring circuit and method. The single storage-battery internal resistance measuring circuit comprises an MCU microcontroller unit, a differential amplifying circuit, a switch driving circuit, a band-pass filtering amplifying circuit, a load resistor, a current sampling resistor and a discharging switch. The load resistor, the current sampling resistor and the discharging switch are connected in series to two ends of a single tested battery, thereby forming a direct-current pulse discharging loop. An input end of the band-pass filtering amplifying circuit is connected to the two ends of the single tested battery, and an output end is connected with an analog-to-digital conversion port ADC2 of the MCU microcontroller unit. An input end of the differential amplifying circuit is connected to two ends of the current sampling resistor, and an output end is connected with an analog-to-digital conversion port ADC1 of the MCU microcontroller unit. An input end of the switch driving circuit is connected with the MCU microcontroller unit, and an output end is connected with the discharging switch. By the invention, measurement can be carried out in batches, unattended operation can be realized, and low cost, high measurement precision and stable performance are achieved.

Description

technical field [0001] The invention relates to a circuit and a measuring method for measuring the internal resistance of a battery cell, which can measure the internal resistance of various battery cells including lead-acid batteries and lithium batteries, and has low cost and high accuracy. Background technique [0002] The internal resistance of the battery is a very important parameter for the performance and quality of the battery. The internal resistance of a fully charged battery must be within the range calibrated by the manufacturer. If the internal resistance is abnormally large at this time, it means that the battery There is a problem. Therefore, it has become the mainstream trend in the current industry to use the internal resistance of the battery to judge whether its performance is good or bad, healthy or not. However, it is not easy to test the internal resistance of a battery, especially a large-capacity battery. The cost of the test instrument used is tens...

AI Technical Summary

Problems solved by technology

[0005] 1) Only large-capacity batteries or batteries can be measured, and small-capacity batteries cannot load a large current of 40A-80A within 2-3 seconds;

[0006] 2) When the battery passes a large current, the electrodes inside the battery will be polarized, resulting in polarization internal resistance

Therefore, the measurement time must be very short, otherwise the error of the measured internal resistance value will be large;

[0007] 3) Large current passing through the battery will cause certain damage to the electrodes inside the battery

The disadvantage of this method is that: the technical content is relatively high, and the cost of designing the product is relatively high, and the relevant technologies are generally in the hands of well-known foreign brand manufacturers.

It is not conducive to large-scale deployment into unattended monitoring application solutions

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