A battery protection circuit and power supply system

Abstract

The invention relates to a battery protection circuit, the battery protection circuit comprising:The internal resistance detecting module (11), the determining module (12) and the prohibiting charging and discharging module (13); wherein the internal resistance detecting module (11) is configured to detect the internal resistance of the battery, and output the detected internal resistance value of the battery To the judging module (12); the judging module (12) is configured to detect the internal resistance value of the battery detected by the internal resistance detecting module (11) and the preset battery in the determining module (12)The resistance value is compared, when the detected internal resistance value of the battery is greater than the predetermined internal resistance value of the battery, the control signal is output to the prohibition charging and discharging module (13); the charging and discharging module (13) is prohibited for prohibiting according to the control signal Charging and / or discharging the battery. The invention can effectively improve the safety of the battery.

Description

technical field [0001] The invention relates to battery protection technology, in particular to a battery protection circuit and a power supply system. Background technique [0002] Due to the advantages of high energy density and light weight of lithium batteries (including lithium ion batteries and lithium polymer batteries), their applications are becoming more and more widespread. However, its safety is worrying, and damaged lithium batteries are prone to dangers such as explosion, fire, and spontaneous combustion. Current lithium battery protection circuits generally include charging overvoltage protection, charging overcurrent protection, discharging overvoltage protection, and discharging overcurrent protection. As the battery ages, part of the free lithium ions will separate and crystallize into metals, which will gather and crystallize locally. In severe cases, it will pierce the insulating film and cause an internal short circuit. The continued use of such a lithi...

AI Technical Summary

Problems solved by technology

As the battery ages, some free lithium ions will separate and crystallize into metals, and gather and crystallize locally. In severe cases, it will pierce the insulating film and cause an internal short circuit. The continued use of such a lithium battery will cause danger.

This aging will cause the internal resistance of the battery to become higher, and then the internal electrical parameters of the battery will change, so that the carrying capacity of the battery will be exceeded, and the probability of battery danger will increase.

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