Power lithium battery protection circuit

Abstract

The utility model relates to the technical field of electric energy storage systems, and discloses a power lithium battery protection circuit. In the utility model, the positive electrode of a battery is connected in series with a power type wire-wound resistor R1 and then is connected to a positive electrode power supply port P +, and the negative electrode of the battery is directly connected to a negative electrode power supply port P-; a power supply control circuit is connected to a link between the positive electrode of the battery and the power type wire-wound resistor R1, the other electrode of the power supply control circuit is connected to an MCU, the MCU is connected with an interface circuit through an activation circuit, the activation circuit is externally connected with a tool fault identification port DO for connection and debugging, and the interface circuit is externally connected with a charger fault identification port CO for communication with a charger. Therefore, through the arrangement of components such as the power type wire-wound resistor, the surge can be easily limited, the secondary protection chip can effectively prevent the components such as the voltage stabilizing chip from being damaged by unstable voltage, fusing protection is provided for the battery pack, and the service life of the battery pack is prolonged. Therefore, the battery pack can have a relatively long service life in a use scene with frequent and large surges.

Description

Technical Field

[0001] This utility model relates to the field of energy storage system technology, and in particular to a device for charging or depolarizing a battery pack or for supplying power from a battery pack to a load. Background Technology

[0002] In the existing technology, the protection circuit for the power lithium battery of DC power tools is limited by size and cannot accommodate too many components. It mainly considers the relatively simple voltage regulation control with buck-boost function. Generally, only a few voltage regulator chips are needed to achieve this. This is mainly suitable for situations where the voltage output is relatively stable. In this case, surges with amplitudes exceeding 20% ​​will not occur frequently.

[0003] However, the inventors discovered that the existing technology has at least the following problems: In some other regions, there are no such voltage output conditions, and frequent surges often occur with unpredictable amplitudes. This makes it easy for ordinary voltage regulator chips to break down, which in turn leads to abnormal battery buck-boost and overcharging damage, resulting in a short battery pack lifespan. The root cause of this short lifespan is that the voltage regulator chip in the battery pack protection circuit has an extremely short lifespan under frequent and large surges. Utility Model Content

[0004] The purpose of this invention is to provide a protection circuit for power lithium batteries, enabling the battery pack to have a longer service life even in frequent and large surge scenarios.

[0005] To solve the above-mentioned technical problems, this utility model provides a power lithium battery protection circuit. A power-type wire-wound resistor R1 is connected in series with the positive terminal of the battery and then connected to the positive power supply port P+. The negative terminal of the battery is directly connected to the negative power supply port P-. A power control circuit is connected to the link between the positive terminal of the battery and the power-type wire-wound resistor R1. The other terminal of the power control circuit is connected to an MCU. The MCU is connected to an interface circuit through an activation circuit. The activation circuit is externally connected to a tool fault identification port DO for connecting and debugging. The interface circuit is externally connected to a charger fault identification port CO for communicating with the charger.

[0006] Each positive terminal of the battery is connected to a secondary protection chip, and the control terminal of the secondary protection chip is connected to the MCU through a connection circuit and an interface circuit.

[0007] A charging management chip is connected to the link between the positive terminal of the battery and the power-type wire-wound resistor R1. The charging management chip is connected to an external Type-C interface.

[0008] An LED 1 is connected in series in the link between the positive terminal of the battery and the power wire-wound resistor R1.

[0009] The MCU is connected to an external button.

[0010] The button is also connected to an activation circuit.

[0011] An LDO is connected between the power control circuit and the MCU.

[0012] The LDO output voltage is 5V, and the LDO output terminal is connected to the MCU.

[0013] The activation circuit is also connected to the power control circuit.

[0014] A variable resistor R2 is connected in parallel between the tool's fault identification port DO and the negative power supply port P-.

[0015] Compared to existing technologies, this invention utilizes components such as power-type wire-wound resistors to easily limit surges. Furthermore, a secondary protection chip effectively prevents voltage instability from damaging components like voltage regulators, providing fuse protection for the battery pack. This allows the battery pack to have a longer service life even in scenarios with frequent and significant surges. Additionally, it provides an independent and simple debugging interface, facilitating rapid fault identification in case of malfunctions. This is particularly beneficial in scenarios with frequent and significant surges, enabling easier maintenance and repair to extend the battery's lifespan.

[0016] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more obvious and understandable, specific embodiments of this utility model are given below. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with the corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings do not constitute a limitation on scale.

[0018] Figure 1 This is a connection diagram of at least one embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the various embodiments of this utility model will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this utility model to facilitate a better understanding of this application. However, the technical solutions claimed in this application can be implemented even without these technical details and with various variations and modifications based on the following embodiments. The division of the various embodiments below is for ease of description and should not constitute any limitation on the specific implementation of this utility model. The various embodiments can be combined with and referenced by each other without contradiction.

[0020] The first embodiment of this utility model relates to a power lithium battery protection circuit. A power-type wire-wound resistor R1 is connected in series with the positive terminal of the battery and then connected to the positive power supply port P+. The negative terminal of the battery is directly connected to the negative power supply port P-. A power control circuit is connected to the link between the positive terminal of the battery and the power-type wire-wound resistor R1. The other terminal of the power control circuit is connected to an MCU. The MCU is connected to an interface circuit through an activation circuit. The activation circuit is externally connected to a tool fault identification port DO for connecting and debugging. The interface circuit is externally connected to a charger fault identification port CO for communicating with the charger.

[0021] Therefore, by using a power-type wire-wound resistor, surge limiting during charging can be achieved, effectively preventing damage caused by frequent surges with only a relatively simple component. Correspondingly, in scenarios with frequent and large surges, the charger fault identification port (CO) can effectively identify charger faults, while the tool fault identification port (DO) can effectively identify power tool faults. This significantly reduces troubleshooting time, facilitates maintenance, and further extends service life.

[0022] It is easy to understand that when the technical solution of this utility model is implemented into a specific product, the MCU is also connected to a screen to display fault information and other content; in addition, the tool fault identification port DO is connected to a 20K±1% pull-down resistor, while the charger fault identification port CO is connected to a 200K±1% pull-down resistor, and the charger external input is 5V / 10K±1%.

[0023] The second embodiment of this utility model is largely the same as the first embodiment, except that each positive terminal of the battery is connected to a secondary protection chip, and the control terminal of the secondary protection chip is connected to the MCU through a connection circuit and an interface circuit.

[0024] Therefore, based on the setting of the secondary protection chip, compared with the first embodiment, even when the surge amplitude is too large, such that the power wire-wound resistor R1 cannot achieve an effective surge limiting effect, the secondary protection chip can still provide fuse protection for the battery and other chips.

[0025] Furthermore, a charging management chip is connected to the link between the battery positive terminal and the power-type wire-wound resistor R1, and the charging management chip is connected to an external Type-C interface. Generally, the maximum voltage provided by the Type-C interface is 20V, so it can be directly connected, and bypassing the protection of the power-type wire-wound resistor R1 can provide higher charging and discharging efficiency.

[0026] Furthermore, an LED1 is connected in series in the link between the positive terminal of the battery and the power-type wire-wound resistor R1. The LED1 is mainly used to indicate the working status.

[0027] Furthermore, the MCU has external buttons. The button configuration provides a reliable and cost-effective basis for local input control of the MCU.

[0028] Furthermore, the button is also connected to an activation circuit. It is easy to understand that in this embodiment, "button" refers to a combination of multiple buttons, wherein at least one button is connected to...

[0029] The third embodiment of this utility model is largely the same as the first embodiment, except that an LDO is further connected between the power control circuit and the MCU.

[0030] Furthermore, the LDO output voltage is 5V, and the LDO output is connected to the MCU. The LDO setting ensures stable MCU operation, allowing the MCU to provide fault information input and output even in the event of a surge-induced fault.

[0031] Furthermore, the activation circuit is also connected to the power control circuit. The activation circuit is mainly used to achieve self-locking under the control of the MCU (generally achieved through transistor-type circuits). Connecting it to the power control circuit facilitates the provision of power supply to the MCU based on the MCU's active control.

[0032] Furthermore, a variable resistor R2 is connected in parallel between the tool fault identification port DO and the negative power supply port P-.

[0033] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A power lithium battery protection circuit, characterized in that, A power-type wire-wound resistor R1 is connected in series with the positive terminal of the battery and then connected to the positive power supply port P+. The negative terminal of the battery is directly connected to the negative power supply port P-. A power control circuit is connected to the link between the positive terminal of the battery and the power-type wire-wound resistor R1. The other terminal of the power control circuit is connected to the MCU. The MCU is connected to the interface circuit through an activation circuit. The activation circuit is externally connected to a tool fault identification port DO for connecting and debugging. The interface circuit is externally connected to a charger fault identification port CO for communicating with the charger.

2. The power lithium battery protection circuit according to claim 1, characterized in that, Each positive terminal of the battery is connected to a secondary protection chip, and the control terminal of the secondary protection chip is connected to the MCU through a connection circuit and an interface circuit.

3. The power lithium battery protection circuit according to claim 1, characterized in that, A charging management chip is connected to the link between the positive terminal of the battery and the power-type wire-wound resistor R1. The charging management chip is connected to an external Type-C interface.

4. The power lithium battery protection circuit according to claim 1, characterized in that, An LED 1 is connected in series in the link between the positive terminal of the battery and the power wire-wound resistor R1.

5. The power lithium battery protection circuit according to claim 1, characterized in that, The MCU is connected to an external button.

6. The power lithium battery protection circuit according to claim 5, characterized in that, The button is also connected to an activation circuit.

7. The power lithium battery protection circuit according to claim 1, characterized in that, A low-dropout linear regulator is connected between the power control circuit and the MCU.

8. The power lithium battery protection circuit according to claim 7, characterized in that, The low-dropout linear regulator has an output voltage of 5V, and its output terminal is connected to the MCU.

9. The power lithium battery protection circuit according to claim 1, characterized in that, The activation circuit is also connected to the power control circuit.

10. The power lithium battery protection circuit according to claim 1, characterized in that, A variable resistor R2 is connected in parallel between the tool's fault identification port DO and the negative power supply port P-.

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