Charge and discharge protector for two-cell lithium ion battery

Abstract

The invention designs a charge and discharge protector for a single-cell lithium ion battery. The charge and discharge protector comprises a discharge control unit, a charge control unit, a lithium ion battery, a recoverable fuse, a charge and discharge positive end, a charge negative end and a discharge negative end. Compared with the prior art, the discharge control unit is only provided with six discrete devices, the charge control unit is also only provided with six discrete devices, the resettable fuse is added, and the whole single-cell lithium ion battery charge and discharge protector is only provided with thirteen conventional discrete devices, so that three protections of over-charge, over-discharge and over-current are realized, the structure is very simple, the cost is very low, and the protector is suitable for protection control of the single-cell lithium ion battery; a charging cut-off voltage and a discharging cut-off voltage can be set, so that the phenomenon of over-charging or over-discharging in the charging and discharging process is prevented; charging protection and discharging protection are independently carried out and do not influence each other, so that the reliability is improved; and the battery discharging loop does not pass through the charging control unit, so that the discharging efficiency of the lithium ion battery is improved.

Description

technical field [0001] The invention relates to a battery management system of a lithium ion battery, in particular to a charge and discharge protector for a lithium ion battery with two batteries. Background technique [0002] Lithium-ion batteries have the advantages of high energy density, good safety performance, and long cycle life, and are widely used in the new energy automobile industry, starting power supply, energy storage market, and military fields. However, if the lithium-ion battery is overcharged, the electrolyte and other materials will decompose and produce gas, which will cause the battery shell or pressure valve to bulge and rupture, and then explode; if the battery voltage is too low, some materials inside the battery will begin to be destroyed, and Because the battery will self-discharge, the longer it is placed, the lower the voltage will be; in addition, when the charging current is too high, lithium ions will not have time to enter the storage cell, a...

AI Technical Summary

Problems solved by technology

[0003] Chinese patent CN112234689B discloses a charge-discharge protection circuit and a lithium-ion battery protection system. Two comparators are used to collect the lithium-ion battery voltage, and a charge-discharge control circuit is formed by a plurality of digital integrated circuits. The structure is relatively complicated. Since only one The MOSFET is used as a power switch, which can only control the charging. If the discharge is to be controlled, the invention also needs to design a MOSFET as a discharge power switch.

[0004] Patent No. CN 104682355 B discloses a lithium-ion battery protection circuit, which requires a special multi-way switch and a voltage comparison circuit, and also requires multiple digital integrated chips to form a logic circuit. In order to realize charge and discharge control, four field effect transistors are used. The control logic is very complex

[0005] In addition, the current charging and discharging protection of lithium-ion batteries mostly uses integrated voltage acquisition and control circuits, which are costly and need to configure control parameters through the host computer. The use process is relatively complicated, which is not conducive to two-cell lithium-ion batteries, or different types Applications of lithium-ion batteries

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