Lead-acid battery BMS management method

Abstract

The invention discloses a lead-acid battery BMS (Battery Management System) management method, a lead-acid battery comprises a plurality of batteries which are connected in series, each battery is provided with a divider resistor connecting branch, each divider resistor connecting branch is provided with a voltage sampling output end, and a voltage signal output by the voltage sampling output end is transmitted to a charging controller; wherein when the lead-acid battery is charged and current corresponding to a voltage signal output by a sampling output end of a certain battery is found to be relatively overlarge, the charging current of the battery is reduced, so that the voltage difference between the battery and other batteries is controlled within a preset range; according to the invention, even if the lead-acid battery is subjected to multiple charging and discharging cycles, the voltage difference of each battery in the lead-acid battery can be controlled within a preset range, so that the lead-acid battery has a longer service life.

Description

Technical Field

[0001] This invention belongs to the field of lead-acid battery management, and specifically relates to a lead-acid battery BMS management method. Background Technology

[0002] Lead-acid batteries remain the primary power source for electric vehicle drive motors. However, there are few battery management systems (BMS) for lead-acid batteries, and existing BMS management systems are typically designed for lithium batteries, making them unsuitable for lead-acid batteries.

[0003] Specifically, in actual operation, the applicant found that after multiple charge-discharge cycles, there would be an increasingly obvious voltage difference between the cells in the lead-acid battery, resulting in a decrease in the cycle life of the lead-acid battery.

[0004] Therefore, the applicant seeks technical solutions to improve the above-mentioned technical problems. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a lead-acid battery BMS management method that can ensure that the voltage difference of each cell in the lead-acid battery is controlled within a preset range even after multiple charge-discharge cycles, thereby giving the lead-acid battery a longer service life.

[0006] The technical solution of the present invention is as follows: A lead-acid battery BMS management method is disclosed, wherein the lead-acid battery includes several cells connected in series, and each cell is provided with a voltage divider resistor connection branch, and the voltage divider resistor connection branch is provided with a sampling output terminal, and the signal output from the sampling output terminal is transmitted to the charging controller; wherein, when the lead-acid battery is charged, if it is found that the current corresponding to the signal output from the sampling output terminal of a certain cell is relatively too large, the charging current of that cell is reduced, so that the voltage difference between that cell and other cells is controlled within a preset range.

[0007] Preferably, when charging the lead-acid battery, the voltage difference between each battery is not higher than 0.6V by controlling the charging current of each battery cell.

[0008] Preferably, when charging the lead-acid battery, the voltage difference between each battery is not higher than 0.4V by controlling the charging current of each battery cell.

[0009] Preferably, the voltage of each battery cell is 10-18V, more preferably 12-15V.

[0010] Preferably, the voltage divider resistor connection branch of each battery cell includes a first voltage divider resistor and a second voltage divider resistor connected in series; wherein, the first voltage divider resistor is connected to the output terminal of each battery cell, and the second voltage divider resistor is grounded.

[0011] Preferably, the connection point between the first voltage divider resistor and the second voltage divider resistor is used as the sampling output terminal.

[0012] Preferably, the voltage divider resistor connection branch of each battery cell is also connected to a switching transistor, which is communicatively connected to the charging controller and is used to selectively perform voltage divider sampling output on a certain battery cell.

[0013] Preferably, the lead-acid battery is equipped with a control board, and the voltage divider resistors of each battery cell are connected to the control board, and the control board is communicatively connected to the charging controller.

[0014] Preferably, the control board is a PCB board.

[0015] Preferably, the control board is mounted on the periphery of the lead-acid battery.

[0016] Preferably, the lead-acid battery comprises 4-8 batteries connected in series, more preferably 5-7 batteries.

[0017] This application proposes a specific BMS management method for lead-acid batteries. Each battery cell is connected to a voltage divider resistor branch, and this branch is equipped with a sampling output terminal. The signal output from the sampling output terminal is then sent to the charging controller. When charging the lead-acid battery, if the current corresponding to the signal output from a certain battery cell is found to be relatively excessive, the charging current of that battery cell is reduced. This ensures that the voltage difference between that battery cell and other batteries is controlled within a preset range. In practical applications, even after multiple charge-discharge cycles, the voltage difference between the lead-acid batteries can be maintained within the preset range, thus extending the battery's lifespan. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the battery connection structure used in the lead-acid battery BMS management method according to a specific embodiment of this application; Figure 2 This is a schematic diagram of the structure of the voltage divider resistor connection branch set in each battery cell in a specific embodiment of this application. Detailed Implementation

[0019] This invention discloses a lead-acid battery BMS management method. The lead-acid battery includes several cells connected in series. Each cell is provided with a voltage divider resistor connection branch, and each voltage divider resistor connection branch is provided with a voltage sampling output terminal. The voltage signal output from the voltage sampling output terminal is sent to the charging controller. When charging the lead-acid battery, if the current corresponding to the voltage signal output from the sampling output terminal of a certain cell is found to be relatively too large, the charging current of that cell is reduced to control the voltage difference between that cell and other cells within a preset range. In actual implementation, the charging controller can directly perform voltage-to-current conversion calculations based on the received voltage signals and output a charging current reduction command to a specified cell according to the corresponding battery value status. These are conventional technical choices that can be made by those skilled in the art based on the content of this application, and this embodiment will not elaborate on this part.

[0020] Preferably, in this embodiment, the lead-acid battery includes 4-8 batteries connected in series, more preferably 5-7 batteries.

[0021] Preferably, in this embodiment, the voltage of each cell in the lead-acid battery is 10-18V, more preferably 12-15V; preferably, in this embodiment, when charging the lead-acid battery, the voltage difference between each cell is not higher than 0.6V by controlling the charging current of each cell; more preferably, when charging the lead-acid battery, the voltage difference between each cell is not higher than 0.4V by controlling the charging current of each cell.

[0022] Preferably, in this embodiment, the voltage divider resistor connection branch of each battery cell includes a first voltage divider resistor R1 and a second voltage divider resistor R2 connected in series; wherein, the first voltage divider resistor R1 is connected to the output terminal of each battery cell, and the second voltage divider resistor R2 is grounded; more preferably, in this embodiment, the connection point between the first voltage divider resistor R1 and the second voltage divider resistor R2 serves as the voltage sampling output terminal.

[0023] Preferably, in order to further achieve flexible control, in this embodiment, the voltage divider resistor connection branch of each battery is also connected to a switching transistor (specifically, a MOSFET or other type of triode switching transistor can be used, and this embodiment does not make any special restrictions on this). The switching transistor is communicatively connected to the charging controller and is used to selectively perform voltage divider sampling output on a certain battery.

[0024] Preferably, in this embodiment, the lead-acid battery is equipped with a control board, and the voltage divider resistors of each battery cell are connected to the control board, and the control board is communicatively connected to the charging controller; more specifically, in this embodiment, the control board is a PCB board, which is installed on the periphery of the lead-acid battery.

[0025] It should be noted that the resistance values ​​of the voltage divider resistors involved in the embodiments of this application can be specifically configured according to the actual charging current and voltage division requirements. These are common knowledge to those skilled in the art and are not considered as separate innovative content of this application.

[0026] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0027] Example 1: Please refer to Figure 1 As shown, a lead-acid battery BMS management method is disclosed. The lead-acid battery includes six batteries connected in series, specifically battery 1, battery 2, battery 3, battery 4, battery 5, and battery 6. The voltage of each battery is 12-13V. A voltage divider resistor connection branch is provided for each battery, specifically branch 1a, branch 2a, branch 3a, branch 4a, branch 5a, and branch 6a. Each voltage divider resistor connection branch is equipped with a voltage sampling output terminal, and the voltage signal output from the voltage sampling output terminal is sent to the charging controller. When charging the lead-acid battery, if the current corresponding to the voltage signal output from the sampling output terminal of a certain battery is found to be relatively too high, the charging current of that battery is reduced to control the voltage difference between that battery and other batteries within 0.4V. In this embodiment, please refer to the following further details. Figure 2 As shown, the voltage divider resistor connection branch for each battery cell includes a first voltage divider resistor R1 and a second voltage divider resistor R2 connected in series; wherein, the first voltage divider resistor R1 is connected to the output terminal U0 of each battery cell, and the second voltage divider resistor R2 is grounded to GND; the connection point between the first voltage divider resistor R1 and the second voltage divider resistor R2 (i.e., the connection point between the first voltage divider resistor R1 and the second voltage divider resistor R2) is... Figure 2 The “sampling point” shown is used as the voltage sampling output terminal U1, which is connected to the charging controller for communication. In this embodiment, a control board 7 (specifically a PCB board) is configured around the lead-acid battery. The voltage divider resistors of each battery cell are connected to the control board 7, and the control board 7 is communicatively connected to the charging controller (a known structure).

[0028] To verify the technical effect of Embodiment 1, this application compared the sampled voltage (obtained from the sampling output terminal of the branch connected to the voltage divider resistor of each battery cell) with the actual voltage (obtained by actual detection), and recorded the voltage as shown in Table 1 below: .

[0029] As shown in Table 1 above, the voltage difference between each battery cell is controlled within 0.4V using the lead-acid battery BMS management method provided in this embodiment 1.

[0030] Example 2: The remaining technical solutions of Example 2 are the same as those of Example 1, except that MOS transistors are further provided in the first voltage divider resistor connection branch 1a, the second voltage divider resistor connection branch 2a, the third voltage divider resistor connection branch 3a, the fourth voltage divider resistor connection branch 4a, the fifth voltage divider resistor connection branch 5a and the sixth voltage divider resistor connection branch 6a. The MOS transistors are connected between the output terminal of their corresponding battery and their corresponding first voltage divider resistor R1. At the same time, each MOS transistor is communicatively connected to the charging controller, thereby realizing selective activation control of each voltage divider resistor connection branch.

[0031] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0032] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A lead-acid battery BMS management method, wherein the lead-acid battery comprises a plurality of batteries connected in series, characterized in that, Each battery cell is connected to a voltage divider resistor branch, and each voltage divider resistor branch is equipped with a sampling output terminal. The signal output from the sampling output terminal is sent to the charging controller. When charging the lead-acid battery, if the current corresponding to the signal output from the sampling output terminal of a certain battery cell is found to be relatively too large, the charging current of that battery cell is reduced so that the voltage difference between that battery cell and other batteries is controlled within a preset range.

2. The lead-acid battery BMS management method according to claim 1, characterized in that, When charging lead-acid batteries, the voltage difference between each cell is controlled to ensure that it does not exceed 0.6V.

3. The lead-acid battery BMS management method according to claim 2, characterized in that, When charging lead-acid batteries, the voltage difference between each battery is kept below 0.4V by controlling the charging current of each battery cell.

4. The lead-acid battery BMS management method according to claim 1, 2, or 3, characterized in that, The voltage of each battery cell is 10-18V, more preferably 12-15V.

5. The lead-acid battery BMS management method according to claim 2, characterized in that, The voltage divider resistor connection branch of each battery includes a first voltage divider resistor (R1) and a second voltage divider resistor (R2) connected in series; wherein, the first voltage divider resistor (R1) is connected to the output terminal of each battery, and the second voltage divider resistor (R2) is grounded.

6. The lead-acid battery BMS management method according to claim 5, characterized in that, The connection point between the first voltage divider resistor (R1) and the second voltage divider resistor (R2) serves as the sampling output terminal.

7. The lead-acid battery BMS management method according to claim 1, 5, or 6, characterized in that, Each battery cell's voltage divider resistor connection branch is also connected to a switching transistor, which is communicatively connected to the charging controller and used to selectively perform voltage divider sampling output on a specific battery cell.

8. The lead-acid battery BMS management method according to claim 1, 5, or 6, characterized in that, The lead-acid battery is equipped with a control board, and the voltage divider resistors of each battery cell are connected to the control board. The control board is also communicatively connected to the charging controller.

9. The lead-acid battery BMS management method according to claim 7, characterized in that, The control board is a PCB board.

10. The lead-acid battery BMS management method according to claim 7, characterized in that, The control board is installed on the periphery of the lead-acid battery.

Images