Battery core internal resistance measuring method and battery core matching method

Abstract

The invention provides a battery core internal resistance measuring method and a battery core matching method to improve battery core internal resistance measuring and matching precision under the condition of being without damage to a battery. The battery core internal resistance measuring method comprises that an alternating current source is used for sending multiple alternating current stimulating signals with different frequencies to a battery core to be measured; multiple response signals corresponding to the multiple alternating current stimulating signals one to one are acquired; and according to the alternating current stimulating signals and the response signals corresponding to each frequency, internal resistance of the battery core to be measured under each frequency is calculated. According to the methods, accuracy of measurement of the internal resistance is improved, and accurate set matching for the internal resistance of the battery core is achieved.

Description

technical field [0001] The invention belongs to the field of electronics, and in particular relates to a battery internal resistance measurement method and a battery matching method. Background technique [0002] The internal resistance of the battery cell is an important technical index to measure the performance of the battery cell. It can not only reflect the state of charge (power) of the battery cell and the performance attenuation during use, but also an important factor affecting the charging and discharging characteristics and efficiency of the battery cell. In the case where multiple battery cells are required to be used in series and in parallel (such as battery packs for notebook computers and battery packs for power vehicles), the internal resistance of the battery cells will directly determine their shunt and voltage division conditions. When the resistance deviation is large (or when the deviation gradually increases during the use of the battery pack), the sta...

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Problems solved by technology

[0003] The DC instantaneous discharge method is to make the cell under test release a load current in an instant, and measure the change of the cell voltage before and after discharge at the same time, obtain the internal resistance of the cell through Ohm's law, and calculate the external load resistance and the cell according to the theory. When the internal resistance is close, the error of the measured result is the smallest, which makes the load current very large (generally more than 10 times the rated capacity of the battery), such a large current may cause irreversible damage to the battery on the one hand; on the other hand Due to the large difference from the daily use conditions of the batteries, the measured results may not accurately reflect the conditions of the batteries in daily use

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