Equalization circuit, battery management system and battery device

Abstract

The invention provides an equalization circuit, a battery management system and a battery device. A battery pack comprises first sampling lines located between two adjacent battery units, each wiring detection end is used for being connected with one first sampling line, a positive electrode wiring end is used for being connected with a positive electrode of the battery pack, and a negative electrode wiring end is used for being connected with a negative electrode of the battery pack; a discharge module is respectively connected in series between the anode access end and each equalization access end, between the cathode access end and each equalization access end, and between any two equalization access ends; and the switch module is used for controlling the connection and disconnection between the positive terminal and the positive access end, the connection and disconnection between the negative terminal and the negative access end, and the connection and disconnection between any one wiring detection end and any one equalization access end. Therefore, voltage balance can be realized under the condition that each first sampling line is connected with the wiring detection end in an out-of-order manner.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management, and in particular to an equalization circuit, a battery management system and a battery device. Background Art

[0002] Electric two-wheeled vehicles are usually powered by battery packs, such as lead-acid battery packs or lithium-ion battery packs containing multiple battery cells. When the battery cells in the battery pack are connected in series, in order to ensure the consistency of the battery cell voltage, an equalization circuit is used to achieve battery voltage balance. The existing equalization circuit sets a resistor for each battery cell, and controls whether the battery cell and the corresponding resistor are turned on by a switch. When the voltage of a battery cell is high or the remaining power is large, the battery cell needs to be discharged, and the corresponding switch is closed so that the voltage or power of the battery is equivalent to the voltage or power of other batteries, thereby achieving voltage balance. Among them, the switch and the resistor can constitute a power consumption module, which is a component of the battery management system (BMS).

[0003] When leaving the factory, each battery cell of the lithium-ion battery pack has been connected and fixed inside the battery pack according to the designed connection structure. When installing it on an electric two-wheeled vehicle, there is no need to connect and install each battery cell. However, lead-acid battery packs are different from lithium-ion battery packs. When installing and using lead-acid battery packs, operators need to connect and install each battery cell to the lead-acid BMS. During the installation process, the sampling lines of different battery cells need to be distinguished and connected to the connection points of the power consumption module in the specified order. If the connection is wrong, the voltage cannot be balanced normally, and the wiring between the battery cell and the BMS needs to be reconnected.

[0004] The above-mentioned process of installing a lead-acid battery pack is usually difficult to complete efficiently and accurately. This connection method increases the workload of the installer and may result in low installation efficiency or connection errors, which may cause the battery management system BMS to not work properly or even be damaged. Summary of the invention

[0005] The present invention provides an equalizing circuit, a battery management system and a battery device, which are used to solve the problem of low battery installation efficiency or connection error, and realize voltage equalization even when battery cells and the equalizing circuit are connected in disorder.

[0006] In a first aspect, the present invention provides a balancing circuit, which is suitable for balancing battery cells in a battery pack formed by connecting N battery cells in series; the battery pack comprises a first sampling line located between two adjacent battery cells, the number of the first sampling lines is N-1, and N is an integer greater than or equal to 3; the balancing circuit comprises:

[0007] N-1 wiring detection terminals, N-1 balancing access terminals, a positive wiring terminal, a negative wiring terminal, a positive access terminal, a negative access terminal and a plurality of discharge modules; each of the wiring detection terminals is used to be connected to one of the first sampling lines, the positive wiring terminal is used to be connected to the positive electrode of the battery pack, and the negative wiring terminal is used to be connected to the negative electrode of the battery pack; a discharge module is connected in series between the positive access terminal and each of the balancing access terminals, between the negative access terminal and each of the balancing access terminals, and between any two of the balancing access terminals;

[0008] A switch module is provided between the N-1 wiring detection terminals, the positive wiring terminal, the negative wiring terminal and the N-1 balancing access terminals, the positive access terminal and the negative access terminal, and the switch module is used to control the on-off between the positive wiring terminal and the positive access terminal, between the negative wiring terminal and the negative access terminal, and between any one of the wiring detection terminals and any one of the balancing access terminals;

[0009] Among them, the discharge module adjacent to the positive electrode access terminal or the negative electrode access terminal belongs to the first group, and the discharge module not adjacent to the positive electrode access terminal and the negative electrode access terminal belongs to the second group, and the difference in equivalent resistance values ​​of each discharge module in the first group is less than a first preset difference threshold; the difference in equivalent resistance values ​​of each discharge module in the second group is less than the first preset difference threshold, and the difference in equivalent resistance values ​​of discharge modules in different groups is greater than a second preset difference threshold, and the second preset difference threshold is greater than the first preset difference threshold.

[0010] In one embodiment, the switch module includes: a first switch, a second switch and N-1 third switches;

[0011] One end of the first switch is used to be connected to the positive terminal, and one end of the second switch is used to be connected to the negative terminal;

[0012] One end of each of the third switches is connected to one of the wiring detection ends, the other end of each of the third switches is connected to one of the balancing access ends, the other end of the first switch is connected to the positive electrode access end, and the other end of the second switch is connected to the negative electrode access end.

[0013] In one embodiment, the balancing circuit further includes a control module;

[0014] The output end of the control module is connected to the input end of the first switch, the input end of the second switch and the input ends of N-1 third switches respectively, and is used to output control information to control whether the battery unit to be discharged is discharged.

[0015] In one embodiment, the equalization circuit further includes an identification module;

[0016] The input end of the identification module is connected to N-1 wiring detection ends; the identification module is used to identify the actual corresponding connection relationship between each of the wiring detection ends and each of the first sampling lines, and send the actual corresponding connection relationship to the control module;

[0017] The control module is also used to determine the battery cell to be discharged according to the status information of each battery cell, determine the target switch according to the actual corresponding connection relationship, and output control information for controlling the closing of the target switch; when the target switch is closed, the battery cell to be discharged is in a discharging state.

[0018] In one embodiment, the balancing circuit further includes: N-1 sampling access terminals; a pair of voltage dividing modules connected in series are respectively connected between one of the negative electrode terminal and the positive electrode terminal and any of the sampling access terminals;

[0019] The input end of the identification module is connected to the series connection point in each pair of voltage divider modules; the identification module is used to obtain the voltage of each wiring detection end respectively when each wiring detection end is connected to the corresponding sampling access end, sort the voltages of each wiring detection end to obtain a sorting result, and determine the actual corresponding connection relationship between each wiring detection end and each first sampling line according to the sorting result.

[0020] In one embodiment, when acquiring the voltage of each of the wiring detection terminals, the identification module is specifically used to:

[0021] The voltage at each of the series connection points is detected respectively, and the voltage at the wiring detection terminal corresponding to the series connection point is determined according to the voltage at each of the series connection points.

[0022] In one embodiment, the control module is further used to determine the battery cell to be discharged according to the voltage of each battery cell;

[0023] The battery cell to be discharged is the battery cell with the largest voltage among the N battery cells.

[0024] In one embodiment, the circuit further includes a power module, which is connected to the identification module and is also connected to the control module; the power module is used to supply power to the identification module and the control module.

[0025] In one embodiment, the equivalent resistance values ​​of the discharge modules in the first group are the same, and / or the equivalent resistance values ​​of the discharge modules in the second group are the same.

[0026] In one embodiment, the first switch is a switch composed of a single P-type MOSFET; and / or, the second switch is a switch composed of a single N-type MOSFET; and / or, the third switch is a bidirectional switch composed of two N-type MOSFETs connected back to back.

[0027] In one embodiment, the discharge module includes a resistor; or, the discharge module includes at least two resistors; and the at least two resistors are connected in series, in parallel, or in a mixed manner.

[0028] In one embodiment, the equivalent resistance value of the discharge module is related to a preset balancing current.

[0029] In a second aspect, the present invention provides a battery management system, comprising the balancing circuit described in any one of the first aspects.

[0030] In a third aspect, the present invention provides a battery device, comprising the battery management system described in the second aspect and a plurality of battery cells.

[0031] In one embodiment, the battery unit is a lead-acid battery; and / or the number of the battery units is 3 to 7.

[0032] The present invention provides a balancing circuit, a battery management system and a battery device, which are suitable for balancing battery cells in a battery pack formed by connecting N battery cells in series; the battery pack includes a first sampling line located between two adjacent battery cells, the number of the first sampling lines is N-1, and N is an integer greater than or equal to 3; the balancing circuit includes: N-1 wiring detection terminals, N-1 balancing access terminals, a positive wiring terminal, a negative wiring terminal, a positive access terminal, a negative access terminal and a plurality of discharge modules; each of the wiring detection terminals is used to be connected to one of the first sampling lines, the positive wiring terminal is used to be connected to the positive electrode of the battery pack, and the negative wiring terminal is used to be connected to the negative electrode of the battery pack; a discharge module is connected in series between the positive access terminal and each of the balancing access terminals, between the negative access terminal and each of the balancing access terminals, and between any two of the balancing access terminals; a switch module is provided between the N-1 wiring detection terminals, the positive wiring terminal and the negative wiring terminal and the N-1 balancing access terminals. The switch module is used to control the on / off between the positive electrode terminal and the positive electrode terminal, between the negative electrode terminal and the negative electrode terminal, and between any one of the wiring detection terminals and any one of the balancing access terminals; wherein the discharge module adjacent to the positive electrode terminal or the negative electrode terminal belongs to the first group, and the discharge module not adjacent to the positive electrode terminal and the negative electrode terminal belongs to the second group, and the difference in equivalent resistance values ​​of each discharge module in the first group is less than a first preset difference threshold; the difference in equivalent resistance values ​​of each discharge module in the second group is less than the first preset difference threshold, and the difference in equivalent resistance values ​​of discharge modules in different groups is greater than a second preset difference threshold, and the second preset difference threshold is greater than the first preset difference threshold, and by setting a plurality of discharge modules and setting the equivalent resistance value of each discharge module, voltage balancing can be achieved even when each first sampling line is connected to the wiring detection terminal in disorder. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0034] Figure 1 It is a structural schematic diagram of an equalizing circuit in the prior art;

[0035] Figure 2 A schematic diagram of the structure of an equalization circuit provided by an embodiment of the present invention;

[0036] Figure 3 A simulation diagram of an equivalent resistance value provided by an embodiment of the present invention Figure 1 ;

[0037] Figure 4 A simulation diagram of an equivalent resistance value provided by an embodiment of the present invention Figure 2 ;

[0038] Figure 5 A simulation diagram of an equivalent resistance value provided by an embodiment of the present invention Figure 3 ;

[0039] Figure 6 A simulation diagram of an equivalent resistance value provided by an embodiment of the present invention Figure 4 ;

[0040] Figure 7 A simulation diagram of an equivalent resistance value provided by an embodiment of the present invention Figure 5 ;

[0041] Figure 8 A simulation diagram of an equivalent resistance value provided by an embodiment of the present invention Figure 6 ;

[0042] Fig. 9 A simulation diagram of an equivalent resistance value provided by an embodiment of the present invention Figure 7 ;

[0043] Fig.10 A simulation diagram of an equivalent resistance value provided by an embodiment of the present invention Figure 8 ;

[0044] Fig.11 A simulation diagram of an equivalent resistance value provided by an embodiment of the present invention Figure 9 ;

[0045] Fig.12 A schematic diagram of the structure of another equalization circuit provided by an embodiment of the present invention;

[0046] Fig.13 A schematic diagram of an overall structure for voltage balancing of battery cells provided by an embodiment of the present invention;

[0047] Fig.14 A schematic diagram of the structure of an identification module provided by an embodiment of the present invention.

[0048] The above drawings have shown clear embodiments of the present invention, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the present invention in any way, but to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0049] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention.

[0050] When a battery pack is a plurality of battery cells connected in series, each battery cell can supply power to the outside. For example, when the battery pack is used in an electric two-wheeled vehicle, the battery pack can provide power for the electric two-wheeled vehicle. Since there are multiple battery cells in the battery pack, when each battery cell supplies power to the outside, there may be a battery cell with a higher voltage or more remaining power, and the voltage or remaining power of different battery cells may differ greatly. In this case, some battery cells need to be discharged to make the voltage or power of the battery cell equivalent to the voltage or power of other battery cells, that is, voltage balancing is required to increase the service life of the battery pack.

[0051] In the related art, when voltage balancing is performed on battery cells, a discharge module and a switch are usually set for each battery cell. When discharging a battery cell, some switches can be controlled to close so that the battery cell is connected to the discharge module. The resistance values ​​of the various discharge modules are not much different. When the wiring is correct, it can be ensured that the balancing current is approximately the same when discharging different battery cells. However, if the wiring is wrong, even if the actual wiring sequence is known, the balancing current will be very different because it is impossible to ensure that the resistance values ​​corresponding to each discharge module are similar. Therefore, it is still necessary to ensure that the wiring is correct before the battery cells can be balanced.

[0052] Figure 1 FIG. 1 is a schematic diagram of a structure of an equalizing circuit in the prior art. Figure 1 As shown, when there are 4 battery cells, four resistors and five switches can be set, P1 to P3 are balancing access terminals, B1 to B3 are sampling lines of the battery pack, wherein the positive electrode of the battery pack can be connected to R4 through switch K5, and the negative electrode of the battery pack can be connected to R1 through switch K1. For P1 to P3, and B1 to B3, there is a fixed connection sequence, that is, B1 is connected to P1, B2 is connected to P2, and B3 is connected to P3. When discharging BAT1, switches K1 and K2 are closed; when discharging BAT2, switches K2 and K3 are closed; when discharging BAT3, switches K3 and K4 are closed; when discharging BAT4, switches K4 and K5 are closed. If a wiring error occurs, for example, P1 is connected to B1 and P3 is connected to B1, if the battery cell BAT4 is to be discharged, the resistance of the balancing resistor connected between B3 and B+ is actually the series resistance of R2, R3, and R4. Compared with the resistance when the wiring is correct (resistor R4), the resistance is almost doubled, so the balancing current will inevitably change greatly.

[0053] In the above technical solution, each sampling line needs to be correctly connected to each balancing access terminal, but in practice, it is difficult to quickly and accurately distinguish each sampling line, so there will be low connection efficiency or connection errors. If the connection is wrong, voltage balancing cannot be performed normally. In order to solve the problem of low connection efficiency or connection errors, the present application considers developing a technical solution that allows each sampling line to be connected to each balancing access terminal in a disorderly order, so that voltage balancing of the battery cell can be achieved even in the case of disordered connection.

[0054] Therefore, the present application sets multiple discharge modules and the equivalent resistance value of each discharge module so that the load impedance corresponding to each battery cell is similar when the battery cells are connected to the balancing circuit in a disorderly order, thereby achieving approximately consistent balancing current and accurately achieving voltage balancing for any battery cell.

[0055] The present invention provides a balancing circuit, which is suitable for balancing battery cells in a battery pack formed by connecting N battery cells in series; the battery pack comprises a first sampling line located between two adjacent battery cells, the number of the first sampling lines is N-1, and N is an integer greater than or equal to 3; the balancing circuit comprises:

[0056] N-1 wiring detection terminals, N-1 balancing access terminals, a positive wiring terminal, a negative wiring terminal, a positive access terminal, a negative access terminal and a plurality of discharge modules; each of the wiring detection terminals is used to be connected to one of the first sampling lines, the positive wiring terminal is used to be connected to the positive electrode of the battery pack, and the negative wiring terminal is used to be connected to the negative electrode of the battery pack; a discharge module is connected in series between the positive access terminal and each of the balancing access terminals, between the negative access terminal and each of the balancing access terminals, and between any two of the balancing access terminals;

[0057] A switch module is provided between the N-1 wiring detection terminals, the positive wiring terminal, the negative wiring terminal and the N-1 balancing access terminals, the positive access terminal and the negative access terminal, and the switch module is used to control the on-off between the positive wiring terminal and the positive access terminal, between the negative wiring terminal and the negative access terminal, and between any one of the wiring detection terminals and any one of the balancing access terminals;

[0058] Among them, the discharge module adjacent to the positive electrode access terminal or the negative electrode access terminal belongs to the first group, and the discharge module not adjacent to the positive electrode access terminal and the negative electrode access terminal belongs to the second group, and the difference in equivalent resistance values ​​of each discharge module in the first group is less than a first preset difference threshold; the difference in equivalent resistance values ​​of each discharge module in the second group is less than the first preset difference threshold, and the difference in equivalent resistance values ​​of discharge modules in different groups is greater than a second preset difference threshold, and the second preset difference threshold is greater than the first preset difference threshold.

[0059] The following will take four battery cells as an example to illustrate the implementation mode of the present invention. Of course, the number of battery cells may also be 3, 5, 6, 7, etc. Figure 2 A structural diagram of an equalization circuit provided by an embodiment of the present invention is shown in FIG. Figure 2 As shown, the circuit structure when N is equal to 4 is shown. In the figure, B1, B2 and B3 are the first sampling lines. When the number of battery cells is 4, the number of first sampling lines is 3. P1, P2 and P3 are wiring detection terminals, and each first sampling line and each wiring detection terminal can be connected in random order. In the figure, points B, C and D are balancing access terminals, point E is the positive access terminal, point A is the negative access terminal, the positive wiring terminal in the balancing circuit is the end connected to B+, the negative wiring terminal is the end connected to B-, B+ is the sampling line connected to the positive pole of the battery pack, and B- is the sampling line connected to the negative pole of the battery pack. In order to achieve voltage balancing for each battery cell, a discharge module is provided between any two points among points A, B, C, D and E (except the combination of points A and E), and there are 9 discharge modules.

[0060] The discharge modules form a load impedance of the battery pack through a series connection, and the discharge modules are used to consume the battery power. When voltage balancing is performed on any battery cell, these 9 discharge modules can all participate in voltage balancing.

[0061] In order to achieve close equalization currents when voltage equalization is performed on each battery cell, the key is to achieve similar resistance values ​​of resistors connected at both ends of each battery cell.

[0062] In order to achieve the above purpose, the equivalent resistance value of each discharge module can be set, and when voltage balancing is performed on any battery unit, the load impedance can be made approximately equal. Among them, the discharge modules can be divided into two groups, the discharge modules adjacent to the positive access terminal or the negative access terminal belong to the first group, and the discharge modules not adjacent to the positive access terminal and the negative access terminal belong to the second group, wherein the difference in the equivalent resistance values ​​of each discharge module in the first group is less than the first preset difference threshold, the difference in the equivalent resistance values ​​of each discharge module in the second group is less than the first preset difference threshold, and the difference in the equivalent resistance values ​​of the discharge modules in different groups is greater than the second preset difference threshold, and the second preset difference threshold is greater than the first preset difference threshold. That is, the equivalent resistance values ​​of each discharge module in the first group are approximately equal, the equivalent resistance values ​​of each discharge module in the second group are approximately equal, and the equivalent resistance values ​​of each discharge module in the first group are not equal to the equivalent resistance values ​​of each discharge module in the second group, and have a certain difference. Among them, the first preset difference and the second preset difference can be set according to the purpose of the present invention.

[0063] For example, Figure 2 R1, R4, R5, R6, R8, and R9 are discharge modules in the first group, and R2, R3, and R7 are discharge modules in the second group. Therefore, the resistance values ​​of R1, R4, R5, R6, R8, and R9 are approximately equal, the resistance values ​​of R2, R3, and R7 are approximately equal, and the resistance value of the discharge module in the first group is different from the resistance value of the discharge module in the second group.

[0064] Figures 3 to 11 The simulation diagram of the equivalent resistance value is shown in FIG. Figures 3 to 11 As shown in the figure, when the equivalent resistance value of the discharge module in the first group is 30Ω and the equivalent resistance value of the discharge module in the second group is 43Ω, the equivalent resistance value of the load impedance formed by the 9 discharge modules is 14.886Ω or 14.659Ω when viewed from any two points other than A and E among points A, B, C, D and E. It can be seen that by setting the resistance value of each discharge module, the equivalent resistance value of the load impedance formed by the 9 discharge modules can be approximately equal when viewed from any two points (except the combination of A and E) among points A, B, C, D and E.

[0065] In addition, a switch module is also provided in the above-mentioned balancing circuit. The switch module can be provided between N-1 wiring detection terminals, the positive wiring terminal and the negative wiring terminal and the N-1 balancing access terminals, the positive access terminal and the negative access terminal. The switch module can be used to connect the battery cell and the balancing access terminal or the positive access terminal or the negative access terminal, so as to balance the voltage of the battery cell.

[0066] When voltage balancing is performed on the battery cells, since the first sampling lines and the balancing access terminals are connected in disorder, after the actual corresponding connection relationship between the first sampling lines and the balancing access terminals is determined, when a battery cell is to be discharged, the switch that needs to be turned on can be determined, and the voltage of the battery cells can be balanced by turning on the switch.

[0067] For example, see Figure 2 , when the actual corresponding connection relationship is: B3 is connected to P3, B2 is connected to P2, and B1 is connected to P1. When it is necessary to control the discharge of battery BAT1, the switches that need to be turned on are K1 and K2; when it is necessary to control the discharge of battery BAT2, the switches that need to be turned on are K2 and K3; when it is necessary to control the discharge of battery BAT3, the switches that need to be turned on are K3 and K4; when it is necessary to control the discharge of battery BAT4, the switches that need to be turned on are K4 and K5.

[0068] Exemplarily, when the actual corresponding connection relationships are: B3 is connected to P3, B1 is connected to P2, and B2 is connected to P1, when it is necessary to control the discharge of battery BAT1, the switches that need to be turned on are K1 and K3; when it is necessary to control the discharge of battery BAT2, the switches that need to be turned on are K2 and K3; when it is necessary to control the discharge of battery BAT3, the switches that need to be turned on are K2 and K4; when it is necessary to control the discharge of battery BAT4, the switches that need to be turned on are K4 and K5.

[0069] Exemplarily, when the actual corresponding connection relationships are: B2 is connected to P3, B1 is connected to P2, and B3 is connected to P1, when it is necessary to control the discharge of battery BAT1, the switches that need to be turned on are K1 and K3; when it is necessary to control the discharge of battery BAT2, the switches that need to be turned on are K3 and K4; when it is necessary to control the discharge of battery BAT3, the switches that need to be turned on are K2 and K4; when it is necessary to control the discharge of battery BAT4, the switches that need to be turned on are K2 and K5.

[0070] Exemplarily, when the actual corresponding connection relationships are: B2 is connected to P3, B3 is connected to P2, and B1 is connected to P1, when it is necessary to control the discharge of battery BAT1, the switches that need to be turned on are K1 and K2; when it is necessary to control the discharge of battery BAT2, the switches that need to be turned on are K2 and K4; when it is necessary to control the discharge of battery BAT3, the switches that need to be turned on are K3 and K4; when it is necessary to control the discharge of battery BAT4, the switches that need to be turned on are K3 and K5.

[0071] Exemplarily, when the actual corresponding connection relationship is: B1 is connected to P3, B2 is connected to P2, and B3 is connected to P1, when it is necessary to control the discharge of battery BAT1, the switches that need to be turned on are K1 and K4; when it is necessary to control the discharge of battery BAT2, the switches that need to be turned on are K3 and K4; when it is necessary to control the discharge of battery BAT3, the switches that need to be turned on are K2 and K3; when it is necessary to control the discharge of battery BAT4, the switches that need to be turned on are K2 and K5.

[0072] Exemplarily, when the actual corresponding connection relationships are: B1 is connected to P3, B3 is connected to P2, and B2 is connected to P1, when it is necessary to control the discharge of battery BAT1, the switches that need to be turned on are K1 and K4; when it is necessary to control the discharge of battery BAT2, the switches that need to be turned on are K2 and K4; when it is necessary to control the discharge of battery BAT3, the switches that need to be turned on are K2 and K3; when it is necessary to control the discharge of battery BAT4, the switches that need to be turned on are K3 and K5.

[0073] In the balancing circuit included in the present invention, when the number of battery cells is 4, B+ and B- need to be connected to the positive terminal and the negative terminal of the balancing circuit respectively, and the other three first sampling lines can be connected to the wiring detection terminal in a disorderly order. In the case of disorderly connection, the balancing circuit can still work correctly, which can simplify the installation process of the first sampling lines, reduce the difficulty of installation, and improve the installation efficiency and reliability.

[0074] The present invention provides a balancing circuit, which is suitable for balancing battery cells in a battery pack formed by connecting N battery cells in series; the battery pack comprises a first sampling line located between two adjacent battery cells, and the number of the first sampling lines is N-1; the balancing circuit comprises: N-1 wiring detection terminals, N-1 balancing access terminals, a positive wiring terminal, a negative wiring terminal, a positive access terminal, a negative access terminal and a plurality of discharge modules; each of the wiring detection terminals is used to be connected to one of the first sampling lines, the positive wiring terminal is used to be connected to the positive electrode of the battery pack, and the negative wiring terminal is used to be connected to the negative electrode of the battery pack; a discharge module is respectively connected in series between the positive access terminal and each of the balancing access terminals, between the negative access terminal and each of the balancing access terminals, and between any two of the balancing access terminals; a switch module is arranged between the N-1 wiring detection terminals, the positive wiring terminal and the negative wiring terminal and the N-1 balancing access terminals, the positive access terminal and the The switch module is used to control the on / off between the positive electrode terminal and the positive electrode terminal, between the negative electrode terminal and the negative electrode terminal, and between any one of the wiring detection terminals and any one of the balancing access terminals; wherein the discharge module adjacent to the positive electrode terminal or the negative electrode terminal belongs to the first group, and the discharge module not adjacent to the positive electrode terminal and the negative electrode terminal belongs to the second group, and the difference in equivalent resistance values ​​of each discharge module in the first group is less than a first preset difference threshold; the difference in equivalent resistance values ​​of each discharge module in the second group is less than the first preset difference threshold, and the difference in equivalent resistance values ​​of discharge modules in different groups is greater than a second preset difference threshold, and the second preset difference threshold is greater than the first preset difference threshold, and by setting a plurality of discharge modules and setting the equivalent resistance value of each discharge module, voltage balancing can be achieved even when each first sampling line is connected to the wiring detection terminal in disorder.

[0075] In one embodiment, the switch module includes: a first switch, a second switch and N-1 third switches;

[0076] One end of the first switch is used to be connected to the positive terminal, and one end of the second switch is used to be connected to the negative terminal;

[0077] One end of each of the third switches is connected to one of the wiring detection ends, the other end of each of the third switches is connected to one of the balancing access ends, the other end of the first switch is connected to the positive electrode access end, and the other end of the second switch is connected to the negative electrode access end.

[0078] The number of switch modules can be set to N+1, including N-1 third switches, one first switch and one second switch, the first switch is used to conduct the positive terminal and the positive access terminal, the second switch is used to conduct the negative terminal and the negative access terminal, and the third switch is used to conduct each wiring detection terminal and the equalization access terminal.

[0079] like Figure 2 As shown, K5 is the first switch, K2, K3 and K4 are the third switches, and K1 is the second switch.

[0080] By setting N+1 switches, it is convenient to individually control the on / off of the path between the positive terminal and the positive access terminal, the path between each wiring detection terminal and the balance access terminal, and the path between the negative terminal and the negative access terminal.

[0081] In one embodiment, the balancing circuit further includes a control module;

[0082] The output end of the control module is connected to the input end of the first switch, the input end of the second switch and the input ends of N-1 third switches respectively, and is used to output control information to control whether the battery unit to be discharged is discharged.

[0083] Fig.12 A schematic diagram of another equalization circuit provided by an embodiment of the present invention. In order to realize voltage equalization of each battery cell, it is necessary to control some switches to be closed. After determining the actual corresponding connection relationship and the battery cell to be discharged, the control module can control the closing of the corresponding switch to realize voltage equalization of the battery cell to be discharged.

[0084] The control information can be a digital signal. For example, when it is necessary to control switches K1 and K2 to be closed, a digital signal 1 is output to K1 and K2, and a digital signal 0 is output to K3, K4 and K5. Digital signal 1 indicates that the control switch is closed, and digital signal 0 indicates that the control switch is open, thereby controlling switches K1 and K2 to be closed, and controlling switches K3, K4 and K5 to be opened.

[0085] By outputting control information through the control module, the state of each switch can be automatically controlled, so as to realize voltage balancing of each battery unit.

[0086] In one embodiment, the equalization circuit further includes an identification module;

[0087] The input end of the identification module is connected to N-1 wiring detection ends; the identification module is used to identify the actual corresponding connection relationship between each of the wiring detection ends and each of the first sampling lines, and send the actual corresponding connection relationship to the control module;

[0088] The control module is also used to determine the battery cell to be discharged according to the status information of each battery cell, determine the target switch according to the actual corresponding connection relationship, and output control information for controlling the closing of the target switch; when the target switch is closed, the battery cell to be discharged is in a discharging state.

[0089] In order to realize the correct control of each switch, it is also necessary to determine the actual corresponding connection relationship between each of the wiring detection terminals and each of the first sampling lines. An identification module may be provided to determine the actual corresponding connection relationship.

[0090] Specifically, the input end of the identification module can be connected to N-1 wiring detection ends. When each wiring detection end is connected to each equalization access end, the identification module can obtain the actual corresponding connection relationship. Fig.12 When B1 is connected to P3, B3 is connected to P2, and B2 is connected to P1, the recognition module can obtain the actual corresponding connection relationship.

[0091] The output end of the recognition module can be connected to the control module. After the recognition module determines the actual corresponding connection relationship, it can send the actual corresponding connection relationship to the control module so that the control module can correctly control whether each switch is closed.

[0092] The control module can also be used to determine the battery cells to be discharged. Specifically, the status information of each battery cell can be obtained, and the battery cells to be discharged can be determined according to the status information. After the battery cells to be discharged are determined, the target switch can be determined according to the actual corresponding connection relationship, and the target switch can be controlled to close, so as to achieve voltage balancing of the battery cells to be discharged.

[0093] Exemplarily, when the control module obtains the actual corresponding connection relationship that B1 is connected to P3, B3 is connected to P2, B2 is connected to P1, and the battery cell to be discharged is BAT1, it can determine that the target switches are K1 and K4, so that K1 and K4 can be controlled to close to discharge the battery cell BAT1 to be discharged.

[0094] Fig.13 This is a schematic diagram of an overall structure for voltage balancing of battery cells provided by an embodiment of the present invention. Fig.13 As shown, the positive terminal, each wiring detection terminal and the negative terminal can be connected to the input terminal of the balancing module respectively. At the same time, the output terminal of the identification module is also connected to the input terminal of the control module. The control module can receive the actual corresponding connection sequence between each wiring detection terminal and each first sampling line output by the identification module, so as to control the corresponding switch to realize the discharge of the battery cell to be discharged.

[0095] Fig.14A structural diagram of an identification module provided by an embodiment of the present invention is shown in FIG. Fig.14 As shown, the identification module includes:

[0096] N-1 wiring detection terminals, N-1 sampling access terminals, a positive terminal, a negative terminal and a plurality of voltage divider modules; each of the wiring detection terminals is used to be connected to any one of the first sampling lines; the positive terminal is used to be connected to the positive electrode of the battery pack, and the negative terminal is used to be connected to the negative electrode of the battery pack; a pair of voltage divider modules connected in series are respectively connected between the reference terminal and any of the sampling access terminals; the reference terminal is the negative terminal or the positive terminal;

[0097] A switch module is provided between the N-1 wiring detection terminals and the N-1 sampling access terminals, and the switch module is used to control the connection and disconnection between each wiring detection terminal and the corresponding sampling access terminal;

[0098] A processing unit is connected to the switch module and is used to output an on-off signal to the switch module. The input end of the control module is connected to the series connection point in each pair of voltage divider modules, and is used to respectively obtain the voltage of each wiring detection end when each wiring detection end is respectively connected to the corresponding sampling access end, and determine the actual corresponding connection relationship between each wiring detection end and each first sampling line according to the obtained voltage of each wiring detection end.

[0099] like Fig.14 As shown, BAT1 to BAT N N battery cells are connected in series, B+ is a sampling line connected to the positive electrode of the battery pack, B- is a sampling line connected to the negative electrode of the battery pack, B+ is connected to the positive terminal in the identification module, and B- is connected to the negative terminal.

[0100] B1 to B N-1 is the first sampling line, N is the number of battery cells, the first sampling line is located at the serial connection point of two adjacent battery cells, P1 to P N-1 There are N-1 wiring detection terminals. When installing the battery unit, each first sampling line needs to be manually connected to each wiring detection terminal. The identification module can obtain the actual corresponding connection relationship between each first sampling line and each wiring detection terminal.

[0101] Optionally, a reference terminal may be provided, which may be a negative terminal or a positive terminal of the battery pack. After the reference terminal is determined, a pair of voltage divider modules may be provided between the reference terminal and the sampling access terminal, such as Figure 1 As shown, the sampling access terminals are point A, point B, point C and point D, and the reference terminal is the negative terminal.

[0102] Since each wiring detection terminal is connected to each first sampling line, the voltage of each wiring detection terminal may be the voltage of a battery cell, or the sum of the voltages of two, three to N-1 battery cells. For lead-acid batteries, the voltage of a battery cell may be 10V to 14V. When N is equal to 5, the voltage of the wiring detection terminal can reach about 50V. When measuring voltage, due to the small measurement range of the voltage measuring device, it is usually impossible to directly measure the voltage of the wiring detection terminal. Therefore, for the identification module, a pair of voltage divider modules are set between the sampling access terminal and the reference wiring terminal, and the control module is connected to the series connection point of each pair of voltage divider modules, so as to obtain the voltage of the series connection point, and then obtain the voltage of the wiring detection terminal.

[0103] Among them, when obtaining the voltage of the wiring detection terminal, in order to obtain the voltage at a series connection point at a certain moment, the on-off between the wiring detection terminal and the sampling access terminal can be controlled by a switch, such as Figure 1 As shown, for P1 to P N-1 These N-1 wiring detection terminals can be respectively provided with a switch, such as switch K1, switch K2, etc. When it is necessary to obtain the voltage of the wiring detection terminal P1, the switch K1 can be closed. At this time, the collected voltage is the voltage at the series connection point between R1 and R2, and the voltage of point P1 can be obtained based on the voltage.

[0104] When the reference wiring terminal is determined, the voltages of the first sampling lines have a certain regularity. Therefore, the actual corresponding connection relationship between each wiring detection terminal and the first sampling line can be determined according to the voltage of each wiring detection terminal.

[0105] For example, when the reference terminal is the negative terminal, when N is 4, that is, there are 4 battery cells connected in series, then U B4 is the voltage of B+ relative to B-, U B4 =U BAT1 +U BAT2 +U BAT3 +U BAT4 ; U B1 is the voltage of B1 relative to B-, U B1 =U BAT1 ; U B2 is the voltage of B2 relative to B-, U B2 =U BAT1 +U BAT2 ; U B3 is the voltage of B3 relative to B-, U B3 =U BAT1 +U BAT2 +U BAT3 It can be seen that U B1 B2 B3 ​​After obtaining the voltages of each P point, for example, the voltage U1 at point P1 is 24V, the voltage U2 at point P2 is 36V, and the voltage U3 at point P3 is 12V, then sorting U1, U2, and U3 from smallest to largest gives U3 < U1 < U2. Since U B1 < U B2 < U B3 , it can be known that U3 = U B1 , U1 = U B2 , U2 = U B3 . Thus, the actual corresponding connection relationship can be obtained as: B1 is connected to P3, B2 is connected to P1, and B3 is connected to P2.

[0106] The actual corresponding connection relationship is determined by the identification module, and the target switch is determined by the control module according to the actual corresponding connection relationship and the battery cell to be discharged, so as to discharge the battery cell to be discharged by closing the target switch.

[0107] In one embodiment, the equalization circuit further includes: N - 1 sampling access terminals; a pair of voltage dividing modules connected in series are respectively connected between one of the negative terminal and the positive terminal and any one of the sampling access terminals;

[0108] The input end of the identification module is connected to the series connection point of each pair of voltage dividing modules; the identification module is used to respectively obtain the voltages of each wiring detection end when each wiring detection end is respectively conducted with the corresponding sampling access terminal, sort the voltages of each wiring detection end to obtain a sorting result, and determine the actual corresponding connection relationship between each wiring detection end and each first sampling line according to the sorting result.

[0109] When determining the actual corresponding connection relationship between each wiring detection end and each first sampling line by using the identification module, it can be achieved by obtaining the voltage of the wiring detection end. As Figure 2 shown, assuming B1 is connected to P1, B2 is connected to P2, and B3 is connected to P3, and the voltages of points P1, P2, and P3 relative to the negative electrode are obtained, then the voltage at point P1 is the voltage of the battery cell BAT1, the voltage at point P2 is the sum of the voltages of BAT1 and BAT2, the voltage at point P3 is the sum of the voltages of BAT1, BAT2, and BAT3, and the voltage at point P3 is greater than the voltage at point P2, and the voltage at point P2 is greater than the voltage at point P1. Therefore, by obtaining the voltages of each wiring detection end and sorting the voltages, the actual corresponding connection relationship between each wiring detection end and each first sampling line can be determined.

[0110] Specifically, N-1 sampling access terminals can be set, and a pair of voltage divider modules connected in series are respectively connected between one of the negative terminal and the positive terminal and any sampling access terminal. The input terminal of the identification module can be connected to the series connection point in each pair of voltage divider modules. The identification module can obtain the voltage at the series connection point, and can obtain the voltage of each wiring detection terminal according to the resistance ratio of the corresponding voltage divider module.

[0111] After obtaining the voltages of each wiring detection terminal, the voltages of each wiring detection terminal can be sorted. For example, they can be arranged in order from small to large or from large to small, and the actual corresponding connection relationship can be determined according to the arrangement order. For example, when N is equal to 4, the wiring detection terminals include P1, P2 and P3, and the arrangement order of the voltages of each P point from small to large is P2, P1 and P3, then it can be determined that point P2 is connected to B1, point P1 is connected to B2, and point P3 is connected to B3.

[0112] By collecting the voltages of the wiring detection terminals and sorting the voltages of the wiring detection terminals, the actual corresponding connection relationship between the wiring detection terminals and the first sampling lines can be accurately determined.

[0113] In one embodiment, when acquiring the voltage of each of the wiring detection terminals, the identification module is specifically used to:

[0114] Detect each of the series connection points (such as Fig.14 The voltage at the E, F, G, H, I) shown in the figure is used to determine the voltage at the wiring detection terminal corresponding to the series connection point according to the voltage at each of the series connection points.

[0115] When obtaining the voltage of each wiring detection terminal, the voltage at the series connection point in each pair of voltage divider modules can be obtained, and the voltage of the wiring detection terminal can be determined based on the voltage at the series connection point. Specifically, the voltage of the wiring detection terminal can be determined based on the resistance ratio of a pair of voltage divider modules and the voltage at the series connection point.

[0116] The voltage at the wiring detection terminal can be indirectly obtained by obtaining the voltage at the series connection point. If the voltage at the wiring detection terminal is measured directly, the voltage at a certain wiring detection terminal may be larger and the voltage at the wiring detection terminal cannot be directly obtained.

[0117] In one embodiment, the control module is further used to determine the battery cell to be discharged according to the voltage of each battery cell;

[0118] The battery cell to be discharged is the battery cell with the largest voltage among the N battery cells.

[0119] When determining the battery cell to be discharged, the voltage of each battery cell can be first obtained, and the voltage of each battery cell can be compared to determine the battery cell to be discharged. The battery cell to be discharged is the battery cell with the largest voltage among the N battery cells. Alternatively, the voltages of the N battery cells are sorted, the battery cell with the highest voltage is the first battery cell, and the battery cell with the second highest voltage is the second battery cell. When the difference between the voltage of the first battery cell and the voltage of the second battery cell is greater than a preset value, the first battery cell is determined as the battery cell to be discharged.

[0120] By accurately determining the battery cells to be discharged, accurate discharge of the battery cells in the battery pack can be achieved.

[0121] In one embodiment, the circuit further includes a power module, which is connected to the identification module and is also connected to the control module; the power module is used to supply power to the identification module and the control module.

[0122] In addition, a power supply module may be provided in the above-mentioned equalization circuit, and the power supply module may supply power to the identification module and the control module.

[0123] In one embodiment, the equivalent resistance values ​​of the discharge modules in the first group are the same, and / or the equivalent resistance values ​​of the discharge modules in the second group are the same.

[0124] In order to improve the effect of voltage balancing on the battery group, the equivalent resistance value of each discharge module in the first group can be set to be the same, and the equivalent resistance value of each discharge module in the second group can be set to be the same. Through the above setting method, the load impedance connected to the circuit when any battery unit is discharged can be similar, so that the balancing current is close when the voltage is balanced.

[0125] In one embodiment, the first switch is a switch composed of a single P-type MOSFET; and / or, the second switch is a switch composed of a single N-type MOSFET; and / or, the third switch is a bidirectional switch composed of two N-type MOSFETs connected back to back.

[0126] For the first switch, the second switch and the third switch, different types of switches can be used due to their different settings. Figure 2 Since the current flowing through the switch may be from left to right or from right to left, the third switch may be a bidirectional switch formed by connecting two N-type MOSFETs back to back. Figure 2 The current flowing through the switch is from left to right, so the first switch can be a switch composed of a single P-type MOSFET. Figure 2The current flowing through the switch is from right to left, so the second switch can be a switch composed of a single N-type MOSFET.

[0127] By setting different types of switches, each switch can be simply and conveniently connected to the balancing circuit.

[0128] In one embodiment, the discharge module includes a resistor; or, the discharge module includes at least two resistors; and the at least two resistors are connected in series, in parallel, or in a mixed manner.

[0129] Each discharge module may be composed of one resistor or at least two resistors. If composed of at least two resistors, they may be connected in series, in parallel or in a mixed manner.

[0130] For example, Figure 3 As shown, the discharge module R1 can be a resistor with a resistance of 30Ω, and can also be composed of two or more resistors. The equivalent resistance of the two or more resistors connected in series, parallel or mixed can be equal to 30Ω.

[0131] In one embodiment, the equivalent resistance value of the discharge module is related to a preset balancing current.

[0132] When voltage balancing is performed on each battery cell in a battery pack, if the balancing current is too large, the battery will be damaged. If the balancing current is too small, the balancing speed will be slow. Therefore, the balancing current needs to be within a certain range, that is, there is a preset range for the balancing current. At the same time, since the approximate range of the battery voltage is known in advance, the voltage of each battery cell in a lead-acid battery is usually 10V to 14V, 10V is the voltage when the battery cell is in a low-power state, and 14V is the voltage when the battery cell is fully charged. Therefore, the equivalent resistance value of each discharge module can be determined based on the range of the battery cell voltage and the preset range of the balancing current.

[0133] The equivalent resistance value of each discharge module can be set by the preset balancing current, thereby improving the accuracy of the equivalent resistance value of each discharge module.

[0134] The present invention further provides a battery management system, comprising the equalization circuit described in the above embodiment.

[0135] The present invention provides a battery device, comprising the battery management system described in the above embodiment and a plurality of battery cells.

[0136] In one embodiment, the battery unit is a lead-acid battery; and / or the number of the battery units is 3 to 7.

[0137] The balancing circuit provided by the present invention can ensure that the battery management system can work normally when the first sampling line is connected to the wiring detection end without distinguishing the line sequence without losing performance, thereby simplifying the installation steps of the battery pack, improving the installation efficiency, and also improving the reliability of the installation.

[0138] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An equalization circuit, characterized in that: Suitable for balancing battery cells in a battery pack formed by connecting N battery cells in series; the battery pack comprises a first sampling line located between two adjacent battery cells, the number of the first sampling lines is N-1, and N is an integer greater than or equal to 3; the balancing circuit comprises: N-1 wiring detection terminals, N-1 balancing access terminals, a positive wiring terminal, a negative wiring terminal, a positive access terminal, a negative access terminal and a plurality of discharge modules; each of the wiring detection terminals is used to be connected to one of the first sampling lines, the positive wiring terminal is used to be connected to the positive electrode of the battery pack, and the negative wiring terminal is used to be connected to the negative electrode of the battery pack; a discharge module is connected in series between the positive access terminal and each of the balancing access terminals, between the negative access terminal and each of the balancing access terminals, and between any two of the balancing access terminals; A switch module is provided between the N-1 wiring detection terminals, the positive wiring terminal, the negative wiring terminal and the N-1 balancing access terminals, the positive access terminal and the negative access terminal, and the switch module is used to control the on-off between the positive wiring terminal and the positive access terminal, between the negative wiring terminal and the negative access terminal, and between any one of the wiring detection terminals and any one of the balancing access terminals; Among them, the discharge module adjacent to the positive electrode access terminal or the negative electrode access terminal belongs to the first group, and the discharge module not adjacent to the positive electrode access terminal and the negative electrode access terminal belongs to the second group, and the difference in equivalent resistance values ​​of each discharge module in the first group is less than a first preset difference threshold; the difference in equivalent resistance values ​​of each discharge module in the second group is less than the first preset difference threshold, and the difference in equivalent resistance values ​​of discharge modules in different groups is greater than a second preset difference threshold, and the second preset difference threshold is greater than the first preset difference threshold.

2. The equalization circuit according to claim 1, characterized in that: The switch module includes: a first switch, a second switch and N-1 third switches; One end of the first switch is used to be connected to the positive terminal, and one end of the second switch is used to be connected to the negative terminal; One end of each of the third switches is connected to one of the wiring detection ends, the other end of each of the third switches is connected to one of the balancing access ends, the other end of the first switch is connected to the positive electrode access end, and the other end of the second switch is connected to the negative electrode access end.

3. The equalizing circuit according to claim 2, characterized in that: The balancing circuit also includes a control module; The output end of the control module is connected to the input end of the first switch, the input end of the second switch and the input ends of N-1 third switches respectively, and is used to output control information to control whether the battery unit to be discharged is discharged.

4. The equalizing circuit according to claim 3, characterized in that: The equalization circuit also includes an identification module; The input end of the identification module is connected to N-1 wiring detection ends; the identification module is used to identify the actual corresponding connection relationship between each of the wiring detection ends and each of the first sampling lines, and send the actual corresponding connection relationship to the control module; The control module is also used to determine the battery cell to be discharged according to the status information of each battery cell, determine the target switch according to the actual corresponding connection relationship, and output control information for controlling the closing of the target switch; when the target switch is closed, the battery cell to be discharged is in a discharging state.

5. The equalizing circuit according to claim 4, characterized in that: The balancing circuit further includes: N-1 sampling access terminals; a pair of voltage dividing modules connected in series are respectively connected between one of the negative electrode terminal and the positive electrode terminal and any of the sampling access terminals; The input end of the identification module is connected to the series connection point in each pair of voltage divider modules; the identification module is used to obtain the voltage of each wiring detection end respectively when each wiring detection end is connected to the corresponding sampling access end, sort the voltages of each wiring detection end to obtain a sorting result, and determine the actual corresponding connection relationship between each wiring detection end and each first sampling line according to the sorting result.

6. The equalizing circuit according to claim 5, characterized in that: When acquiring the voltage of each of the wiring detection terminals, the identification module is specifically used to: The voltage at each of the series connection points is detected respectively, and the voltage at the wiring detection terminal corresponding to the series connection point is determined according to the voltage at each of the series connection points.

7. The equalizing circuit according to claim 4, characterized in that: The control module is also used to determine the battery cell to be discharged according to the voltage of each battery cell; The battery cell to be discharged is the battery cell with the largest voltage among the N battery cells.

8. The equalizing circuit according to claim 4, characterized in that: The circuit also includes a power module, which is connected to the identification module and is also connected to the control module; the power module is used to supply power to the identification module and the control module.

9. The equalizing circuit according to claim 1, characterized in that: The equivalent resistance values ​​of the discharge modules in the first group are all the same, and / or the equivalent resistance values ​​of the discharge modules in the second group are all the same.

10. The equalizing circuit according to claim 2, characterized in that: The first switch is a switch composed of a single P-type MOSFET; and / or, the second switch is a switch composed of a single N-type MOSFET; and / or, the third switch is a bidirectional switch composed of two N-type MOSFETs connected back to back.

11. The equalization circuit according to any one of claims 1 to 10, characterized in that: The discharge module includes a resistor; or, the discharge module includes at least two resistors; the at least two resistors are connected in series, in parallel or in a mixed manner.

12. The equalization circuit according to any one of claims 1 to 10, characterized in that: The equivalent resistance value of the discharge module is related to a preset balancing current.

13. A battery management system, characterized in that: The device comprises an equalizing circuit as claimed in any one of claims 1 to 12.

14. A battery device, characterized in that: The invention comprises a battery management system as claimed in claim 13 and a plurality of battery cells.

15. The battery device according to claim 14, characterized in that: The battery cells are lead-acid batteries; and / or the number of the battery cells is 3 to 7.

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