Four series lithium battery protection circuit

Abstract

This utility model discloses a four-cell lithium battery protection circuit. The four-cell lithium battery consists of four cells connected in series. The positive and negative terminals B+ and B- of the lithium battery are connected to the positive and negative charging terminals P+ and P- for charging, respectively. A charge / discharge MOSFET is connected in series on the negative charging line. The lithium battery protection circuit includes a protection chip U1 HTL6024AAHYT16 / R6. The protection chip U1 collects the voltage of each cell of the lithium battery and connects to control the on / off state of the charge / discharge MOSFET, thereby controlling the charging and discharging of the lithium battery. The four-cell lithium battery protection circuit of this utility model uses the HTL6024AAHYT16 / R6 protection chip to achieve five-fold protection against overcharge, over-discharge, overcurrent, short circuit, and high / low temperature. Each protection parameter is independently adjustable to adapt to different application scenarios, and the protection response time is shortened to 0.5ms.

Description

Technical Field

[0001] This utility model belongs to the field of lithium-ion battery technology, and in particular relates to a four-cell lithium battery protection circuit. Background Technology

[0002] Lithium batteries have advantages such as high energy density, long service life, high rated voltage, high power handling capacity, low self-discharge rate, light weight, and strong adaptability to high and low temperatures. They require protection circuits to prevent overcharging, over-discharging, overcurrent, short circuit, and over-temperature protection.

[0003] Existing technologies employ a discrete comparator + MOSFET architecture, which suffers from response delay, a large number of components, and poor parameter consistency. Utility Model Content

[0004] The purpose of this invention is to provide a four-cell lithium battery protection circuit that provides the battery pack with externally adjustable functions for overcharge, over-discharge, overcurrent during charge / discharge, and high / low temperature protection.

[0005] The technical solution of this utility model is:

[0006] A four-cell lithium battery protection circuit is used, wherein the four-cell lithium batteries are composed of four cells connected in series. The positive and negative terminals B+ and B- of the lithium batteries are connected to the positive and negative charging terminals P+ and P- for charging, respectively. A charge / discharge MOSFET is connected in series on the negative charging line. The lithium battery protection circuit includes a protection chip U1 HTL6024AAHYT16 / R6. The protection chip U1 collects the voltage of each cell of the lithium battery and connects to control the on / off state of the charge / discharge MOSFET, thereby controlling the charging and discharging of the lithium battery.

[0007] Preferably, the charging and discharging MOSFETs include a charging MOSFET Q1 and a discharging MOSFET Q2; the charging MOSFET Q1 and the discharging MOSFET Q2 are connected in series on the negative charging line; wherein the charging control pin CHC of the protection chip U1 is connected to control the gate of the charging MOSFET Q1, and the discharging control pin DHC of the protection chip U1 is connected to control the gate of the discharging MOSFET Q2.

[0008] Preferably, the charging / discharging MOS transistor is further connected in parallel with a capacitor assembly, which includes capacitors C11 and C12 connected in series.

[0009] Preferably, the temperature detection pin UTS of the protection chip U1 is grounded through a thermistor, which detects the temperature of the lithium battery.

[0010] The advantages of this utility model are:

[0011] The four-cell lithium battery protection circuit of this utility model adopts the HTL6024AAHYT16 / R6 protection chip to achieve five-fold protection against overcharge, over-discharge, overcurrent, short circuit, and high and low temperatures. Each protection parameter is independently adjustable to adapt to different application scenarios and the protection response time is shortened to 0.5ms. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0013] Figure 1 This is a schematic diagram of the four-cell lithium battery protection circuit of this utility model. Detailed Implementation

[0014] like Figure 1 As shown, the present invention discloses a four-cell lithium battery protection circuit. The four-cell lithium battery consists of four cells connected in series. The positive and negative terminals B+ and B- of the lithium battery are connected to the positive and negative charging terminals P+ and P- for charging, respectively. A charge / discharge MOSFET is connected in series on the negative charging line. The lithium battery protection circuit includes a protection chip U1 HTL6024AAHYT16 / R6. The protection chip U1 collects the voltages B1-B4 of each cell of the lithium battery and connects to control the on / off state of the charge / discharge MOSFET, thereby controlling the charging and discharging of the lithium battery.

[0015] The charge / discharge MOSFETs include a charging MOSFET Q1 and a discharging MOSFET Q2; the charging MOSFET Q1 and the discharging MOSFET Q2 are connected in series on the negative charging line; the charging control pin CHC of the protection chip U1 is connected to control the gate of the charging MOSFET Q1, and the discharging control pin DHC of the protection chip U1 is connected to control the gate of the discharging MOSFET Q2. The charge / discharge MOSFETs are also connected in parallel with a capacitor assembly, which includes capacitors C11 and C12 connected in series.

[0016] When the protection board is working normally, the lithium battery is charging. When each cell reaches 4.175V, the output level of the HTL6024AAHYT16 / R6CHC port changes from the normal high level to the low level, causing the charging MOSFET Q1 to turn off. When each cell discharges to 2.7V, the output level of the HTL6024AAHYT16 / R6 DHC port changes from the normal high level to the low level, causing the discharging MOSFET Q2 to turn off, thus achieving the protection function.

[0017] The temperature detection pin UTS of the protection chip U1 is grounded through a thermistor, which detects the temperature of the lithium battery. When the temperature exceeds the set temperature, the charging and discharging process is stopped.

[0018] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All modifications made in accordance with the spirit and essence of the main technical solution of this utility model should be included within the scope of protection of this utility model.

Claims

1. A four-cell lithium battery protection circuit, characterized in that, The four-cell lithium battery consists of four cells connected in series. The positive and negative terminals B+ and B- of the lithium battery are connected to the positive and negative charging terminals P+ and P- for charging, respectively. A charging / discharging MOSFET is connected in series on the negative charging line. The lithium battery protection circuit includes a protection chip U1 HTL6024AAHYT16 / R6. The protection chip U1 collects the voltage of each cell of the lithium battery and connects to control the on / off state of the charging / discharging MOSFET, thereby controlling the charging and discharging of the lithium battery.

2. The four-cell lithium battery protection circuit according to claim 1, characterized in that, The charging and discharging MOSFETs include a charging MOSFET Q1 and a discharging MOSFET Q2; the charging MOSFET Q1 and the discharging MOSFET Q2 are connected in series on the negative charging line; wherein the charging control pin CHC of the protection chip U1 is connected to control the gate of the charging MOSFET Q1, and the discharging control pin DHC of the protection chip U1 is connected to control the gate of the discharging MOSFET Q2.

3. The four-cell lithium battery protection circuit according to claim 2, characterized in that, The charging / discharging MOSFET is also connected in parallel with a capacitor assembly, which includes capacitors C11 and C12 connected in series.

4. The four-cell lithium battery protection circuit according to claim 3, characterized in that, The temperature detection pin UTS of the protection chip U1 is grounded through a thermistor, which detects the temperature of the lithium battery.

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