Five-string lithium battery protection circuit

Abstract

The utility model discloses a five series lithium battery protection circuit, five series lithium battery is composed of five electric core series connection, and the positive pole B+ of lithium battery is connected positive pole charging terminal C+ respectively, positive pole discharge terminal P+, and the negative pole B of lithium battery is connected negative pole charging terminal P, and the positive pole charging terminal C+ has the charging MOS pipe in series, and the negative pole charging terminal P has the discharge MOS pipe in series, the lithium battery protection circuit includes protection chip U1, and protection chip U1 gathers the voltage of each electric core of lithium battery, and the on-off of control charge, discharge MOS pipe is connected, and then control the charge and discharge of lithium battery, the utility model discloses five series lithium battery protection circuit, adopts CW1074ALBS protection chip, realizes overcharge, overdischarge, overcurrent, short circuit, high and low temperature fivefold protection, and each protection parameter is independently adjustable, and adapts to the demand of different application scene.

Description

Technical Field

[0001] This utility model belongs to the field of lithium-ion battery technology, and in particular relates to a five-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 five-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: A five-cell lithium battery protection circuit is provided, wherein the five-cell lithium battery consists of five cells connected in series. The positive terminal B+ of the lithium battery is connected to the positive charging terminal C+ and the positive discharging terminal P+, respectively; the negative terminal B- of the lithium battery is connected to the negative charging terminal P-; a charging MOSFET is connected in series to the positive charging terminal C+, and a discharging MOSFET is connected in series to the negative charging terminal P-; the lithium battery protection circuit includes a protection chip U1; the protection chip U1 collects the voltage of each cell of the lithium battery, connects to control the on / off state of the charging and discharging MOSFETs, and thus controls the charging and discharging of the lithium battery.

[0006] Preferably, the charging MOSFETs include MOSFETs Q1, Q2, Q10, and Q11, wherein Q1 and Q10 are connected in parallel, and Q2 and Q11 are connected in parallel. The two sets of parallel MOSFETs are connected in series on the positive charging line. The charging control pin CO of the protection chip U1 is connected to control the gates of Q1 and Q10 through MOSFET Q3, and the charging control pin CO is connected to control the gates of Q2 and Q11 through MOSFET Q4.

[0007] Preferably, the discharge MOSFETs include MOSFETs Q7 and Q8 connected in parallel; the discharge control pin DO of the protection chip U1 is connected to the gate of the discharge MOSFETs Q7 and Q8.

[0008] Preferably, when the lithium battery is charged to 4.175V for any cell, the output level of the charging control pin CO of the protection chip U1 changes from the normal high level to the low level, causing the charging MOSFETs Q1, Q2, Q10, and Q11 to be turned off; when any cell is discharged to 2.7V, the output level of the discharging control pin DO of the protection chip U1 changes from the normal high level to the low level, causing the discharging MOSFETs Q7 and Q8 to be turned off, thereby achieving the protection function.

[0009] The protection chip U1 is a CW1074ALBS.

[0010] The advantages of this utility model are: The five-cell lithium battery protection circuit of this invention uses the CW1074ALBS 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 meet the needs of different application scenarios. Attached Figure Description

[0011] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the five-cell lithium battery protection circuit of this utility model. Detailed Implementation

[0012] like Figure 1 As shown, the present invention discloses a five-cell lithium battery protection circuit. The five-cell lithium battery consists of five cells connected in series. The positive terminal B+ of the lithium battery is connected to the positive charging terminal C+ and the positive discharging terminal P+. The negative terminal B- of the lithium battery is connected to the negative charging terminal P-. A charging MOSFET is connected in series to the positive charging terminal C+, and a discharging MOSFET is connected in series to the negative charging terminal P-. The lithium battery protection circuit includes a protection chip U1. 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 and discharging MOSFETs, thereby controlling the charging and discharging of the lithium battery.

[0013] The lithium battery of this invention adopts separate charging and discharging ports. During charging, the C+ and P- terminals are connected, and during discharging, the P+ and P- terminals are connected.

[0014] The charging MOSFETs include MOSFETs Q1, Q2, Q10, and Q11, wherein Q1 and Q10 are connected in parallel, and Q2 and Q11 are connected in parallel. The two sets of parallel MOSFETs are connected in series on the positive charging line. The charging control pin CO of the protection chip U1 is connected to control the gates of Q1 and Q10 through MOSFET Q3, and the charging control pin CO is connected to control the gates of Q2 and Q11 through MOSFET Q4.

[0015] The discharge MOSFETs include MOSFETs Q7 and Q8 connected in parallel; the discharge control pin DO of the protection chip U1 is connected to the gate of the discharge MOSFETs Q7 and Q8.

[0016] When the lithium battery is charged to 4.175V for any cell, the output level of the charging control pin CO of the protection chip U1 changes from the normal high level to the low level, causing the charging MOSFETs Q1, Q2, Q10, and Q11 to turn off. When any cell is discharged to 2.7V, the output level of the discharging control pin DO of the protection chip U1 changes from the normal high level to the low level, causing the discharging MOSFETs Q7 and Q8 to turn off, thus providing protection.

[0017] 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 five-cell lithium battery protection circuit, characterized in that, The five-cell lithium battery consists of five cells connected in series. The positive terminal B+ of the lithium battery is connected to the positive charging terminal C+ and the positive discharging terminal P+. The negative terminal B- of the lithium battery is connected to the negative charging terminal P-. A charging MOSFET is connected in series to the positive charging terminal C+, and a discharging MOSFET is connected in series to the negative charging terminal P-. The lithium battery protection circuit includes a protection chip U1. 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 and discharging MOSFETs, thereby controlling the charging and discharging of the lithium battery.

2. The five-cell lithium battery protection circuit according to claim 1, characterized in that, The charging MOSFETs include MOSFETs Q1, Q2, Q10, and Q11, wherein Q1 and Q10 are connected in parallel, and Q2 and Q11 are connected in parallel. The two sets of parallel MOSFETs are connected in series on the positive charging line. The charging control pin CO of the protection chip U1 is connected to control the gates of Q1 and Q10 through MOSFET Q3, and the charging control pin CO is connected to control the gates of Q2 and Q11 through MOSFET Q4.

3. The five-cell lithium battery protection circuit according to claim 2, characterized in that, The discharge MOSFETs include MOSFETs Q7 and Q8 connected in parallel; the discharge control pin DO of the protection chip U1 is connected to the gate of the discharge MOSFETs Q7 and Q8.

4. The five-cell lithium battery protection circuit according to claim 3, characterized in that, When the lithium battery is charged to 4.175V for any cell, the output level of the charging control pin CO of the protection chip U1 changes from the normal high level to the low level, causing the charging MOSFETs Q1, Q2, Q10, and Q11 to turn off. When any cell is discharged to 2.7V, the output level of the discharging control pin DO of the protection chip U1 changes from the normal high level to the low level, causing the discharging MOSFETs Q7 and Q8 to turn off, thus providing protection.

5. The five-cell lithium battery protection circuit according to claim 1, characterized in that, The protection chip U1 is a CW1074ALBS.

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