BMS with heating function prevents charger reverse connection system

Abstract

The utility model discloses a BMS prevents charger reverse connection system with heating function, including lithium battery group, control chip MCU, the lithium battery group includes positive terminal and negative terminal, there is heating device in series between the positive terminal and negative terminal, the heating device is used for adjusting the temperature of lithium battery group, the SDA pin, SCL pin and GND pin of control chip MCU are connected with detection module respectively, detection module is connected with lithium battery group and is used for detecting the current, voltage and temperature of lithium battery group, the lithium battery group is connected with charger through control chip MCU, and the charging MOSFET is used for controlling the opening or close of charger, there is discharge MOSFET and charging MOSFET in series between detection module and negative terminal, when the multiple electric core of lithium battery group is parallelly connected reverse connection or the positive and negative of heating device reverse connection, the detection module detects that charging or discharging current exceeds predetermined threshold value, and cuts off the circuit.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery systems, and in particular to a BMS system with heating function to prevent reverse connection of the charger. Background Technology

[0002] Currently, lithium batteries, as a new type of energy storage chemical device, have the characteristics of high energy density, long service life, and green environmental protection. Therefore, they have been vigorously promoted worldwide and are increasingly being used in social industry and human life. However, because the materials of lithium batteries are chemical materials such as metallic lithium, nickel, and lithium cobalt oxide, the elements are highly reactive and can easily cause safety problems when used incorrectly.

[0003] The most significant issue is reverse polarity, so lithium batteries must be equipped with appropriate protection circuits. This patent addresses a problem that arises when users operate the battery improperly, or when using a lithium battery as a lead-acid battery, leading to reverse polarity and potential fire.

[0004] Furthermore, existing lithium batteries are generally equipped with heating devices to ensure constant temperature. When the positive and negative terminals of a lithium battery pack are reversed, the heating device will continue to work, which may seriously damage the battery due to high temperature. Utility Model Content

[0005] The main purpose of this invention is to propose a BMS system with heating function to prevent reverse connection of the charger. The aim is to improve the safety of the battery system by avoiding the safety problems caused by the heating device working continuously due to reverse connection of the positive and negative terminals of the lithium battery through the design of the controller and control module.

[0006] To achieve the above objectives, this utility model proposes a BMS system with heating function to prevent reverse connection of the charger, comprising:

[0007] A lithium battery pack, comprising a positive terminal and a negative terminal,

[0008] A heating device is connected in series between the positive and negative terminals, and the heating device is used to regulate the temperature of the lithium battery pack.

[0009] The control chip MCU has its SDA, SCL and GND pins connected to the detection module, which is connected to the lithium battery pack and used to detect the current, voltage and temperature of the lithium battery pack.

[0010] The lithium battery pack is connected to the charger via a control chip MCU, and the charging MOSFET is used to control the charger to turn on or off.

[0011] A discharge MOSFET and a charging MOSFET are connected in series between the detection module and the negative terminal.

[0012] The charging MOSFET is connected in series with the heating device via sampling resistors MA1 and MA2.

[0013] The heating MOSFETs are connected to the control chip MCU, sampling resistor MA1, and sampling resistor MA2, respectively.

[0014] When multiple cells of a lithium battery pack are connected in parallel and reversed, or when the positive and negative terminals of a heating device are reversed...

[0015] The detection module detects that the charging or discharging current exceeds a predetermined threshold and then cuts off the circuit.

[0016] In practical circuit system design,

[0017] 1. When the control chip MCU detects that the lithium battery is at a low temperature, it turns off the charging MOSFET (i.e., turns off the charger), and charging is not allowed at this time;

[0018] The heating MOSFET is turned on, and the heating device (PTC) starts working until the temperature rises to the allowable operating range of the lithium battery cell. Then the heating MOSFET is turned off and the charging MOSFET is turned on to charge the lithium battery normally.

[0019] 2. When the charger is reverse-connected or the batteries are connected in parallel but reverse-connected, the detection module detects that the charging or discharging current exceeds a predetermined threshold, triggering protection (which then disconnects the connection between each lithium battery or the entire discharging circuit).

[0020] When the heating MOSFETs MA1 and MA2 are reversed, the current will not flow through the heating film, thus ensuring that the battery cell will not thermally run away when the charger is reversed.

[0021] 3. When the MCU main control chip performs internal program clock design and adopts countdown, the heating function will be turned off after 2 hours. The heating MOSFET will be disconnected and the current will not flow through the heating film. Therefore, it can be ensured that the battery cell will not thermally run away when the charger is reversed. Attached Figure Description

[0022] Figure 1 This is a circuit diagram of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0024] It should be noted that if any directional indication (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.) is involved in the embodiments of this utility model, the directional indication is only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0025] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0026] like Figure 1 As shown, a BMS system with heating function to prevent reverse connection of the charger includes,

[0027] A lithium battery pack, comprising a positive terminal and a negative terminal,

[0028] A heating device is connected in series between the positive and negative terminals, and the heating device is used to regulate the temperature of the lithium battery pack.

[0029] The control chip MCU has its SDA, SCL and GND pins connected to the detection module, which is connected to the lithium battery pack and used to detect the current, voltage and temperature of the lithium battery pack.

[0030] The lithium battery pack is connected to the charger via a control chip MCU, and the charging MOSFET is used to control the charger to turn on or off.

[0031] A discharge MOSFET and a charging MOSFET are connected in series between the detection module and the negative terminal.

[0032] The charging MOSFET is connected in series with the heating device via sampling resistors MA1 and MA2.

[0033] The heating MOSFETs are connected to the control chip MCU, sampling resistor MA1, and sampling resistor MA2, respectively.

[0034] When multiple cells of a lithium battery pack are connected in parallel and reversed, or when the positive and negative terminals of a heating device are reversed...

[0035] The detection module detects that the charging or discharging current exceeds a predetermined threshold and then cuts off the circuit.

[0036] In practical circuit system design,

[0037] 1. When the control chip MCU detects that the lithium battery is at a low temperature, it turns off the charging MOSFET (i.e., turns off the charger), and charging is not allowed at this time;

[0038] The heating MOSFET is turned on, and the heating device (PTC) starts working until the temperature rises to the allowable operating range of the lithium battery cell. Then the heating MOSFET is turned off and the charging MOSFET is turned on to charge the lithium battery normally.

[0039] 2. When the charger is reversed or the batteries are connected in parallel but reversed, the detection module detects that the charging or discharging current exceeds a predetermined threshold, triggering protection (which then disconnects the connection between each lithium battery or the entire discharging circuit).

[0040] When the heating MOSFETs MA1 and MA2 are reversed, the current will not flow through the heating film, thus ensuring that the battery cell will not thermally run away when the charger is reversed.

[0041] 3. When the MCU main control chip performs internal program clock design and adopts countdown, the heating function will be turned off after 2 hours. The heating MOSFET will be disconnected and the current will not flow through the heating film. Therefore, it can be ensured that the battery cell will not thermally run away when the charger is reversed.

[0042] This application uses three MOSFETs to control charging, discharging, and heating, and solves the problem of reverse connection through a relatively simple control chip, thus improving the stability of use.

[0043] Specifically, the sampling resistors MA1 and MA2 have opposite electrode directions.

[0044] When the heating MOSFETs MA1 and MA2 are reversed, current will not flow through the heating film, thus ensuring that the battery cell will not thermally run away when the charger is reversed.

[0045] Specifically, when the detection module detects that the temperature of the lithium battery pack is lower than a predetermined threshold,

[0046] The charging MOSFET is turned off, and the control chip MCU turns on the heating MOSFET.

[0047] Specifically, the model of the control chip MCU is N32L406. The N32L406 series adopts 32-bit -M4F core, with a main frequency of 64MHz, supports floating-point operation and DSP instructions, integrates up to 128KB embedded Flash and 24KB SRAM, integrates a variety of high-performance analog devices, including one 12-bit 4.5Msps ADC, 2 independent rail-to-rail operational amplifiers, 2 high-speed comparators, one 1Msps 12-bit DAC, integrates communication interfaces such as U(S)ART, LPUART, I2C, SPI, USB, CAN and a Segment LCD driving interface, and has built-in multiple cryptographic algorithm hardware acceleration engines. After mass production, it has been widely recognized by the market and become a popular low-power MCU product.

[0048] Specifically, the heating device is a PTC heating module, so that the temperature can be accurately controlled.

[0049] Specifically, the control chip MCU is provided with a clock, and the clock is used to control the turn-on time of the heating MOSFET.

[0050] Specifically, the battery pack is formed by connecting a plurality of individual batteries in parallel.

[0051] Specifically, the control chip MCU continuously compares the voltage between BATT+ and BATT- (or GND).

[0052] Correct polarity: when BATT+ > BATT- and BATT- is internally connected or equivalent to the system GND), the control chip MCU determines that the polarity is correct.

[0053] Wrong polarity (reverse connection): when BATT+ < BATT-, the actual voltage is negative at this time, and the IC detects the reverse connection state.

[0054] Correct polarity: the detection part will close the internal main power path (by driving the internal or associated MOSFET to conduct). This enables the BATT+ of the battery to be connected to the back-end "PH-" node (the path pointing to the left side of the heating MOSFET in the figure) and possible other system power lines (not explicitly drawn in the figure) through the detection part, and at the same time enables the BATT- path to be connected to the system GND.

[0055] Incorrect polarity (reverse connection): The detection section will disconnect the internal main power path (turn off the internal / associated MOSFET), completely preventing current from flowing from BATT- to "PH-" or system GND, thereby protecting the downstream MCU, heating circuit, etc. from damage.

[0056] MA1: Connected in series on the main path from BATT to GND. The overall measurement system includes key sampling points for measuring the battery discharge current from the heated load.

[0057] MA2: Connected in series in the current loop (PH-to-heating loop) of this specific branch of the heating MOSFET / heating device. The MA2 resistor is specifically designed for precise measurement of the heating current.

[0058] By measuring the voltage drop across these two resistors, the detection unit or MCU can calculate the system discharge current and heating current respectively, which can be used for monitoring, protection (overcurrent judgment) and system management.

[0059] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A BMS system for preventing reverse connection of a charger with a heating function, characterized in that, include, A lithium battery pack, comprising a positive terminal and a negative terminal, A heating device is connected in series between the positive and negative terminals, and the heating device is used to regulate the temperature of the lithium battery pack. The control chip MCU has its SDA, SCL and GND pins connected to the detection module, which is connected to the lithium battery pack and used to detect the current, voltage and temperature of the lithium battery pack. A discharge MOSFET and a charging MOSFET are connected in series between the detection module and the negative terminal. The lithium battery pack is connected to the charger via a control chip MCU, and the charging MOSFET is used to control the charger to turn on or off. The charging MOSFET is connected in series with the heating device via sampling resistors MA1 and MA2. The heating MOSFET is connected to the control chip MCU, sampling resistor MA1, and sampling resistor MA2, respectively. When multiple cells of a lithium battery pack are connected in parallel and reversed, or when the positive and negative terminals of a heating device are reversed... The detection module detects that the charging or discharging current exceeds a predetermined threshold and then cuts off the circuit.

2. The BMS with heating function prevents reverse connection of the charger system according to claim 1, wherein: The sampling resistors MA1 and MA2 have opposite electrode orientations.

3. The BMS with heating function prevents reverse connection of the charger system according to claim 1, wherein: When the detection module detects that the temperature of the lithium battery pack is lower than a predetermined threshold, When the charging MOSFET is turned off, the control chip MCU turns on the heating MOSFET.

4. The BMS with heating function prevents reverse connection of the charger system according to claim 1, wherein: The control chip MCU is model N32L406.

5. The BMS with heating function prevents reverse connection of the charger system according to claim 1, wherein: The heating device is a PTC heating module.

6. The BMS with heating function prevents reverse connection of charger system according to claim 1, wherein: The control chip MCU is equipped with a clock, which is used to control the on-time of the heating MOSFET.

7. The BMS with heating function prevents reverse connection of charger system according to claim 1, wherein: The battery pack consists of multiple individual batteries connected in parallel.

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