Over-discharge prevention and recharge dual protection circuit

Abstract

The utility model provides a kind of overdischarge prevents double protection circuit of recharging, belong to protection circuit technical field, and the following technical scheme is proposed, including electric core positive terminal B1, electric core negative terminal B2, output positive terminal P1, output negative terminal P2, thermosensitive output end T, first resistance R1, second resistance R2, first capacitor C1 and second capacitor C2;With electric core positive terminal B1 and electric core negative terminal B2 electrical connection's detection module U1;With detection module U1 electrical connection's first protection module U2 and second protection module U3;There is overcurrent protection component F1 between electric core positive terminal B1 and output positive terminal P1 in series;Second protection module U3 with the thermosensitive output end T between electrical connection has thermistor R3, this double protection circuit can realize double overcharge protection, overdischarge protection, overcurrent protection, short-circuit protection, and overdischarge after preventing recharging protection, improve security.

Description

Technical Field

[0001] This utility model belongs to the field of protection circuit technology, and more specifically, it relates to a dual protection circuit for over-discharge to prevent recharging. Background Technology

[0002] Lithium-ion batteries, with their advantages of high energy density, long cycle life, and low self-discharge rate, have become a core power source for consumer electronics, smart homes, medical devices, and new energy storage. From smartphones and laptops to smart wearable devices, from household emergency lights to industrial sensors, the widespread application of lithium-ion batteries has greatly promoted the miniaturization and portability of various products. However, the chemical characteristics of lithium-ion batteries mean that they face the risk of deep over-discharge during long-term storage, especially for products that need to be stored for a long time or as backup, often for 3 to 5 years or even longer.

[0003] Even with a low self-discharge rate, lithium batteries will gradually deplete their charge due to continuous internal chemical reactions when left idle for extended periods, eventually entering a state of deep over-discharge. At this point, the electrolyte inside the battery will decompose, the electrode material structure will be damaged, and there may even be hidden dangers such as dendrite short circuits. More importantly, when end users unknowingly charge a lithium battery that has already been deeply over-discharged, the battery may experience violent chemical reactions due to a sudden surge in current, leading to a rapid accumulation of heat, which can then cause leakage, bulging, or even an explosion. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a dual protection circuit for over-discharge and recharge prevention. The purpose and effect of this dual protection circuit for over-discharge and recharge prevention are achieved by the following specific technical means: A dual protection circuit for over-discharge prevention and recharge includes: The positive terminal of the battery cell is B1, the negative terminal of the battery cell is B2, the positive output terminal is P1, the negative output terminal is P2, the thermistor output terminal is T, the first resistor is R1, the second resistor is R2, the first capacitor is C1 and the second capacitor is C2. A detection module U1 is electrically connected to the positive terminal B1 and the negative terminal B2 of the battery cell. The first protection module U2 and the second protection module U3 are electrically connected to the detection module U1; An overcurrent protection component F1 is connected in series between the positive terminal B1 of the battery cell and the positive terminal P1 of the output. The second protection module U3 is electrically connected to the thermistor R3 between itself and the thermistor output terminal T.

[0005] As a further embodiment of this utility model, the detection module U1 includes a Vout terminal a1, a VIN terminal b1, and a VSS terminal c1. Both the first protection module U2 and the second protection module U3 include a VT terminal d1, a GND terminal e1, a VDD terminal f1, a VM terminal g1, and a VM terminal g2.

[0006] As a further embodiment of this utility model, the positive terminal B1 of the battery cell is electrically connected to the VIN terminal b1 of the detection module U1, the VSS terminal c1 of the detection module U1 is electrically connected to the second resistor R2, and the second resistor R2 is electrically connected to the negative terminal B2 of the battery cell.

[0007] As a further embodiment of this utility model, the Vout terminal a1 of the detection module U1 is electrically connected to the first resistor R1, the output terminal of the first resistor R1 is electrically connected to the VDD terminal f1 of the first protection module U2 and the VDD terminal f1 of the second protection module U3 respectively, and the negative terminal B2 of the battery cell is electrically connected to the GND terminal e1 of the first protection module.

[0008] As a further embodiment of this utility model, the VM terminals g1 and g2 of the first protection module U2 are both electrically connected to the GND terminal e1 of the second protection module U3, the VM terminal g1 of the second protection module U3 is electrically connected to the third resistor R3, and the VM terminal g2 of the second protection module U3 is electrically connected to the output negative terminal P2.

[0009] As a further embodiment of this invention, the third resistor R3 is electrically connected to the thermistor output terminal T.

[0010] As a further embodiment of this utility model, a first capacitor C1 is connected between the first resistor R1 and the negative terminal B2 of the battery cell; A second capacitor C2 is electrically connected between the first resistor R1 and the second protection module U3.

[0011] Compared with the prior art, the present invention has the following beneficial effects: This dual protection circuit provides dual overcharge protection, over-discharge protection, overcurrent protection, short circuit protection, and protection against recharging after over-discharge. In cases where the lithium battery has been stored for 3-5 years without use, it protects the lithium battery from recharging through a variety of flexibly adjustable protection modes, thereby improving safety. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a dual protection circuit for over-discharge prevention and recharging according to the present invention. Detailed Implementation

[0013] The embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of this utility model. Example

[0014] As attached Figure 1 : A dual protection circuit for over-discharge prevention and recharge includes: The positive terminal of the battery cell is B1, the negative terminal of the battery cell is B2, the positive output terminal is P1, the negative output terminal is P2, the thermistor output terminal is T, the first resistor is R1, the second resistor is R2, the first capacitor is C1 and the second capacitor is C2. A detection module U1 is electrically connected to the positive terminal B1 and the negative terminal B2 of the battery cell. The first protection module U2 and the second protection module U3 are electrically connected to the detection module U1; An overcurrent protection component F1 is connected in series between the positive terminal B1 of the battery cell and the positive terminal P1 of the output. The second protection module U3 is electrically connected to the thermistor R3 between itself and the thermistor output terminal T.

[0015] Specifically, the detection module U1 includes a Vout terminal a1, a VIN terminal b1, and a VSS terminal c1; Both the first protection module U2 and the second protection module U3 include a VT terminal d1, a GND terminal e1, a VDD terminal f1, a VM terminal g1, and a VM terminal g2.

[0016] Furthermore, the positive terminal B1 of the battery cell is electrically connected to the VIN terminal b1 of the detection module U1, the VSS terminal c1 of the detection module U1 is electrically connected to the second resistor R2, and the second resistor R2 is electrically connected to the negative terminal B2 of the battery cell.

[0017] Furthermore, the Vout terminal a1 of the detection module U1 is electrically connected to the first resistor R1, the output terminal of the first resistor R1 is electrically connected to the VDD terminal f1 of the first protection module U2 and the VDD terminal f1 of the second protection module U3 respectively, and the negative terminal B2 of the battery cell is electrically connected to the GND terminal e1 of the first protection module.

[0018] Furthermore, the VM terminals g1 and g2 of the first protection module U2 are both electrically connected to the GND terminal e1 of the second protection module U3, the VM terminal g1 of the second protection module U3 is electrically connected to the third resistor R3, and the VM terminal g2 of the second protection module U3 is electrically connected to the output negative terminal P2.

[0019] Furthermore, the third resistor R3 is electrically connected to the thermistor output terminal T.

[0020] Furthermore, a first capacitor C1 is connected between the first resistor R1 and the negative terminal B2 of the battery cell; a second capacitor C2 is electrically connected between the first resistor R1 and the second protection module U3.

[0021] In this embodiment, the positive terminal B1 and the negative terminal B2 of the battery cell are connected to the positive and negative terminals of the lithium-ion battery cell (call). The positive terminal B1 is connected in series with the PTC overcurrent protection component F1 and then outputs to the positive output terminal P1. The detection module U1 uses the LN61CC2202MR-G chip, and the first protection module U2 and the second protection module U3 use the XB5350D0 chip. When the detection module U1 detects that the battery cell voltage is ≤2.2V, the output voltage of the Vout terminal a1 is low, which prevents the first protection module U2 and the second protection module U3 from working normally. When the first protection module U2 and the second protection module U3 cannot work normally, the negative terminal B2 of the battery cell and the negative output terminal P2 are in an open circuit state, which plays a role in preventing recharging after over-discharge.

[0022] When the cell voltage is ≤2.2V, the first protection module U1 will conduct electricity from the positive terminal B1 of the cell to the output of the MOSFET inside the first protection module U1 to the VSS terminal c1. The second resistor R2 is connected from the VSS terminal c1 to the negative terminal B2 of the cell, and the remaining trace amount of electricity in the cell is consumed through the second resistor R2. This prevents the cell from being over-discharged, and the VDD terminal f1 of the second protection module U2 and the second protection module U3 will not be energized, thus preventing charging and discharging.

[0023] In this embodiment, when the cell voltage is >2.2V, the first protection module U1 will conduct electricity from the positive terminal B1 of the cell to the output of the MOSFET inside the first protection module U1 to the Vout terminal a1. The first resistor R1 connected to the Vout terminal a1 supplies power to the VDD terminal f1 of the lithium protection chip of the second protection module U2 and the second protection module U3, so that the lithium protection chip of the second protection module U2 and the second protection module U3 can work normally and achieve dual protection.

[0024] In this embodiment, when the cell voltage is >2.2V, the negative terminal B2 of the cell provides the GND terminal e1 of the second protection module U2. When the second protection module U2 detects normal operation, the VM terminal g2 and VM terminal g1 output to the GND terminal e1 of the third protection module U3. When the second protection module U2 detects normal operation, the VM terminal g2 and VM terminal g1 output to the negative terminal P2.

[0025] Specifically, when the second protection module U2 and the second protection module U3 detect overcurrent, overcharge, over-discharge, or short circuit, there will be no output, and the negative terminal B2 of the battery cell and the negative terminal P2 of the output will be in an open circuit state.

[0026] Specifically, overcurrent protection is activated when the input / output current exceeds the set value of the XB5350D0 chip, and an open circuit state is formed between the negative terminal B2 of the battery cell and the negative output terminal P2.

[0027] Specifically, overcharge protection is activated when the voltage across the positive terminal B1 and negative terminal B2 of the battery cell exceeds the set value of the XB5350D0 chip, and an open circuit state is formed between the negative terminal B2 of the battery cell and the negative output terminal P2.

[0028] Specifically, over-discharge protection is activated when the voltage across the positive terminal B1 and negative terminal B2 of the battery cell is lower than the set value of the XB5350D0 chip, and an open circuit state is formed between the negative terminal B2 of the battery cell and the negative output terminal P2.

[0029] Specifically, short-circuit protection is activated when the corresponding parameter exceeds the internally set value of the XB5350D0 chip, and an open circuit state is formed between the negative terminal B2 of the battery cell and the negative output terminal P2.

[0030] It should be noted that for lithium batteries with a capacity ranging from 150mAh to 3000mAh, double overcharge protection, over-discharge protection, overcurrent protection, short-circuit protection, and recharging prevention protection after over-discharge can all be implemented, and the overcurrent protection threshold of the PTC can be adjusted according to the capacity of the lithium battery and output current requirements.

[0031] Embodiments of the present utility model are provided for purposes of illustration and description, and are not intended to be exhaustive or to limit the utility model to the forms disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present utility model, and to enable those of ordinary skill in the art to understand the present utility model so as to design various embodiments with various modifications suitable for specific applications.

Claims

1. A dual protection circuit for over-discharge and recharge prevention, characterized in that, include: The positive terminal of the battery cell is B1, the negative terminal of the battery cell is B2, the positive output terminal is P1, the negative output terminal is P2, the thermistor output terminal is T, the first resistor is R1, the second resistor is R2, the first capacitor is C1 and the second capacitor is C2. Detection module U1 is electrically connected to the positive terminal B1 and the negative terminal B2 of the battery cell; The first protection module U2 and the second protection module U3 are electrically connected to the detection module U1; An overcurrent protection component F1 is connected in series between the positive terminal B1 of the battery cell and the positive terminal P1 of the output. The second protection module U3 is electrically connected to the thermistor R3 between itself and the thermistor output terminal T.

2. The dual protection circuit for over-discharge and recharge prevention as described in claim 1, characterized in that: The detection module U1 includes a Vout terminal a1, a VIN terminal b1, and a VSS terminal c1. Both the first protection module U2 and the second protection module U3 include a VT terminal d1, a GND terminal e1, a VDD terminal f1, a VM terminal g1, and a VM terminal g2.

3. The over-discharge prevention and recharge dual protection circuit as described in claim 2, characterized in that: The positive terminal B1 of the battery cell is electrically connected to the VIN terminal b1 of the detection module U1, the VSS terminal c1 of the detection module U1 is electrically connected to the second resistor R2, and the second resistor R2 is electrically connected to the negative terminal B2 of the battery cell.

4. The over-discharge prevention and recharge dual protection circuit as described in claim 2, characterized in that: The Vout terminal a1 of the detection module U1 is electrically connected to the first resistor R1. The output terminal of the first resistor R1 is electrically connected to the VDD terminal f1 of the first protection module U2 and the VDD terminal f1 of the second protection module U3, respectively. The negative terminal B2 of the battery cell is electrically connected to the GND terminal e1 of the first protection module.

5. The over-discharge prevention and recharge dual protection circuit as described in claim 2, characterized in that: The VM terminals g1 and g2 of the first protection module U2 are both electrically connected to the GND terminal e1 of the second protection module U3. The VM terminal g1 of the second protection module U3 is electrically connected to the third resistor R3. The VM terminal g2 of the second protection module U3 is electrically connected to the output negative terminal P2.

6. The over-discharge prevention and recharge dual protection circuit as described in claim 5, characterized in that: The third resistor R3 is electrically connected to the thermistor output terminal T.

7. The over-discharge prevention and recharge dual protection circuit as described in claim 1, characterized in that: A first capacitor C1 is connected between the first resistor R1 and the negative terminal B2 of the battery cell; A second capacitor C2 is electrically connected between the first resistor R1 and the second protection module U3.

Images