A battery management device and battery pack based on PCB-CCS large current passive balancing
By utilizing a high-current passive balancing scheme based on PCB-CCS, and employing a distributed resistor circuit and a wide copper foil serpentine network structure, the problems of low balancing current and heat dissipation in existing technologies are solved, achieving efficient and rapid battery balancing, which is suitable for high-capacity power batteries.
Patent Information
- Application Number
- CN202521918847.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-05
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-09-05
AI Technical Summary
Existing passive balancing technology has low balancing current, slow balancing speed, and serious heat dissipation problems, which leads to local temperature rise in the battery pack, posing safety hazards, and is difficult to adapt to thin and light battery packs.
A high-current passive balancing scheme based on PCB-CCS is adopted. High-current balancing is achieved through distributed resistor circuits and wide copper foil serpentine network structure. Combined with an independent foldable resistor network PI heating element, the heat dissipation area is increased and the balancing circuit is integrated to avoid local overheating.
The equalization current has been increased to 10A, the equalization speed has been increased by more than 10 times, and the maximum temperature rise has been controlled to ≤40℃. This solves the space and thermal reliability bottlenecks of traditional solutions and provides a low-cost, mass-producible equalization solution for high-capacity batteries.
Smart Images
Figure CN224683144U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a high-current passive balancing battery management device and battery pack based on PCB-CCS, and to the technical field of power battery or energy storage battery management system. Background Technology
[0002] Passive balancing technology is commonly used in power battery management systems (BMS).
[0003] The principle of passive balancing technology is that when the battery pack is charging, if the voltage of a certain cell is detected to be too high, the BMS control switch closes, so that the cell and the parallel resistor form a discharge circuit. The discharge circuit consumes electrical energy through the resistor to reduce the voltage of the cell. The excess energy of the cell is released as heat, which buys more charging time for other cells. This reduces the difference between the cells in the battery pack, making the voltage of each cell close to the same, thus ensuring the overall safety and lifespan of the battery pack.
[0004] Existing passive balancing technology has certain drawbacks. The balancing current is relatively small, usually less than 1A, which results in a slow balancing speed. This is especially true when the battery pack has a large capacity or is severely unbalanced, requiring a longer time to reach equilibrium. In addition, existing passive balancing technology has serious heat dissipation problems. Resistance heating causes local temperature increases in the battery pack, posing a safety hazard to heat-sensitive power batteries.
[0005] In existing technologies, a separate BMU slave control PCB board is set up in the BMS system, and parallel resistors are placed on the BMU board for independent energy dissipation. This design structure makes the balancing resistor and switch too concentrated. To prevent overheating, the balancing current is usually small (tens to hundreds of milliamps), resulting in a slow balancing speed. A reasonable heat dissipation scheme needs to be designed to dissipate the heat generated by the resistors and prevent local overheating from affecting battery life or safety.
[0006] Therefore, existing technologies have shortcomings and need to be improved and perfected. Utility Model Content
[0007] To address the shortcomings of the existing technology, the purpose of this invention is to provide a high-current passive balancing battery management device based on PCB-CCS. According to the embodiments of this utility model, the first solution is: a high-current passive equalization battery management device based on PCB-CCS, including a PCB body and at least one resistor network PI heating element. The PCB body is provided with at least two signal acquisition units. Each signal acquisition unit includes a signal acquisition circuit, a nickel plate, and a switching circuit. Each signal acquisition circuit is connected to one or a group of high-current balancing circuits. The high-current balancing circuit includes a distributed resistor circuit, which serves as a parallel resistor for energy dissipation of a single battery cell. Each high-current balancing circuit is set on a resistor network PI heating element, or multiple high-current balancing circuits are integrated on a resistor network PI heating element.
[0008] Furthermore, the positive or negative terminal of each individual cell is connected to the signal acquisition circuit via a nickel plate. When the voltage acquired by the signal acquisition circuit exceeds a preset threshold, the switching circuit connects the high-current balancing circuit connected in parallel to the individual cell to dissipate energy.
[0009] Furthermore, a resistor network PI heating element is provided on each side of the PCB body. The PCB body is located on one side of the battery pack terminal. The high-current balancing circuits of the PCB body connected to the first side battery pack are all located on the resistor network PI heating element near the first side. The high-current balancing circuits of the PCB body connected to the second side battery pack are all located on the resistor network PI heating element near the second side.
[0010] Furthermore, the signal acquisition unit also includes an NTC sensor, and multiple signal acquisition units are connected to an endplate connector located at one end of the PCB.
[0011] Furthermore, the distributed resistance circuit is a wide copper foil trace or a heating film trace, and the distributed resistance circuit is integrated with or separately connected to the signal acquisition circuit.
[0012] Furthermore, each signal acquisition circuit is connected to two high-current equalization circuits, and the two high-current equalization circuits and the resistor network PI heating element are independently arranged on both sides of the single cell.
[0013] Furthermore, the resistor network PI heating element is connected to the PCB body via wires from a high-current balancing circuit.
[0014] Furthermore, a thermally conductive double-sided adhesive is provided on the back of the resistor network PI heating element, and the resistor network PI heating element is connected to the side of the individual battery cell through the thermally conductive double-sided adhesive.
[0015] Furthermore, a heat dissipation system is provided at the bottom of the battery pack, and the PI heating element of the resistor network attached to the side of the individual battery cell after folding extends toward the heat dissipation system.
[0016] According to the embodiments of this utility model, utilizing the high-current passive balancing battery management device based on PCB-CCS in the first solution provided by this utility model, a second solution is provided as follows: A battery pack includes a PCB-CCS-based high-current passive balancing battery management device. The PCB-CCS-based high-current passive balancing battery management device includes a PCB body and at least one resistor network PI heating element. The PCB body is provided with at least two signal acquisition units, each signal acquisition unit including a signal acquisition circuit, a nickel plate, and a switching circuit. Each signal acquisition circuit is connected to one or a group of high-current balancing circuits. The high-current balancing circuit includes a distributed resistor circuit, which serves as a parallel resistor for energy dissipation of individual battery cells. Each high-current balancing circuit is disposed on one resistor network PI heating element, or multiple high-current balancing circuits are integrated on one resistor network PI heating element.
[0017] Compared with the prior art, the unique advantages of the technical solution provided in this application are as follows: First, this solution increases the passive balancing current from <1A in the traditional solution to 10A, with a single cell balancing power of up to 32W and a balancing speed that is more than 10 times faster. This can meet the fast balancing requirements of high-capacity battery packs. The distributed resistor circuit can be set as a double-sided parallel serpentine resistor network to distribute the 10A total current evenly to both sides of the single cell, 5A on each side. Combined with 1.5mm wide copper foil traces, this ensures current carrying capacity and path balance, avoiding local overload. Secondly, the heat dissipation area of the wide copper foil serpentine resistor network is increased several times, which can control the maximum temperature rise to ≤40℃, solving the problem of insulation failure or material aging caused by local high temperature of traditional centralized resistors. The equalization control chip is placed on the main control PCB and connected to FPC-CCS through a high-speed communication interface, avoiding thermal interference of resistor heating to the chip and improving the stability of system parameters. This solution integrates the discrete power resistors, which are independently mounted on the BMU in existing technologies, onto the PCB-CCS for the first time. It highly integrates a complete equalization circuit, including a distributed resistor network, a MOSFET switch array, and voltage / temperature acquisition lines, within a limited space. This solves the technical problem that discrete high-power resistors occupy a large space and are difficult to adapt to thin and light battery packs.
[0018] Secondly, the high-current balancing circuit and the resistor network PI heating element are independently foldable. In addition to increasing the heat dissipation area, the folded high-current balancing circuit can be attached to both sides of the individual cell, which not only makes reasonable use of the limited space, but also combines with the heat dissipation structure of the individual cell itself to further improve the heat dissipation efficiency of the high-current balancing circuit.
[0019] This invention, through a highly integrated high-current balancing circuit, improves the efficiency of passive balancing while solving the space limitations and thermal reliability bottlenecks of traditional solutions, providing a low-cost, mass-producible balancing solution for high-capacity power batteries. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] in: Figure 1 This is a schematic diagram of the composition of a high-current passive equalization battery management device based on PCB-CCS in one embodiment; Figure 2 This is a schematic diagram illustrating the interaction between a high-current passive balancing battery management device based on PCB-CCS and a battery pack in one embodiment.
[0022] Figure label: 10-PCB body; 11-Nickel sheet; 111-NTC sensor; 12-Aluminum busbar; 13-End board connector; 14-Resistor network PI heating element; 141-Wire; 20-Single battery cell. Detailed Implementation
[0023] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application 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 application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0024] Example 1 For a 13-cell 280Ah power battery pack, with a single cell voltage of 3.2V and a total capacity of 32kWh, the traditional passive balancing scheme of the BMS (Battery Management System) has a balancing current of <1A and requires more than 6 hours to complete balancing. The passive balancing circuit usually uses a separate BMU (Battery Module Unit) with parallel resistors. The resistors are discrete high-power resistors. This passive balancing scheme occupies a lot of space and the local temperature rise of the resistors exceeds 80℃.
[0025] This embodiment provides a high-current passive balancing battery management device based on PCB-CCS, such as... Figure 1 , Figure 2As shown, the device includes a PCB body 10 and at least one resistor network PI heating element 14. The PCB body 10 is equipped with at least two signal acquisition units, each including a signal acquisition circuit, a nickel plate 11, and a switching circuit. Each signal acquisition circuit is connected to one or a group of high-current balancing circuits. The high-current balancing circuit includes a distributed resistor circuit, which serves as a parallel resistor for energy dissipation in a single battery cell 20. Each high-current balancing circuit is mounted on one resistor network PI heating element 14, or multiple high-current balancing circuits are integrated on one resistor network PI heating element 14. The positive or negative terminal of each group of single battery cells 20 is connected to the signal acquisition circuit via an aluminum busbar 12 and a nickel plate 11. When the voltage acquired by the signal acquisition circuit exceeds a preset threshold, the switching circuit activates the high-current balancing circuit connected in parallel to the single battery cell 20 for energy dissipation.
[0026] In a preferred embodiment, a resistor network PI heating element 14 is provided on each side of the PCB body 10. The PCB body 10 is located on one side of the battery pack terminal post. The high current balancing circuits of the PCB body 10 connected to the first side battery pack are all located on the resistor network PI heating element 14 near the first side. The high current balancing circuits of the PCB body 10 connected to the second side battery pack are all located on the resistor network PI heating element 14 near the second side.
[0027] Specifically, the signal acquisition unit also includes an NTC sensor 111, and multiple signal acquisition units are connected to an end board connector 13 located at one end of the PCB.
[0028] Specifically, the distributed resistance circuit is a wide copper foil trace or a heating film trace, and the distributed resistance circuit is integrated with or separately connected to the signal acquisition circuit.
[0029] For example, the split connection allows each signal acquisition circuit to be connected to two high-current equalization circuits. The two high-current equalization circuits and the resistor network PI heating element 14 are independently arranged on both sides of the individual battery cell 20. The switching circuit uses one MOSFET switch, which is connected in parallel to control the on / off state of the equalization circuits on both sides. Each high-current equalization circuit supports a maximum current of 10A, which is controlled by the MOSFET switch to shunt to the first and second shunt branches. The current in the first and second shunt branches can be 5A each. The first and second shunt branches include distributed resistor circuits. These distributed resistor circuits are configured with 1oz wide copper foil traces and designed with a serpentine network structure to increase the length of the distributed resistor circuit. Compared to traditional discrete resistors, the wide copper foil traces of the serpentine network structure significantly improve resistance power and heat dissipation area.
[0030] The signal acquisition circuit monitors the voltage of each cell in real time. When the voltage of a cell exceeds a preset threshold (e.g., 3.65V), a signal is sent to the switching circuit. The MOSFET switch closes to activate the equalization function. The cell discharges through a double-sided serpentine resistor network structure, with a current of 5A on each side and a total equalization current of 10A. During the equalization process, the NTC sensor 111 monitors the cell temperature. If the temperature rise exceeds 40℃, the control IC reduces the duty cycle through the PWM signal, limiting the current to 8A. When the voltage deviation of all cells is ≤20mV, the switching circuit is disconnected, and the equalization is completed.
[0031] By using wide copper foil directly as the balancing resistor to replace traditional discrete resistors, the structure itself becomes the function. A serpentine topology disperses heat, and thermally conductive materials enhance heat conduction, overcoming the bottleneck of high-current, high-temperature passive balancing. An independent resistor network PI heating element 14 can be folded and fitted to both sides of the battery cell, adapting to various cell shapes such as cylindrical and prismatic cells, offering superior compatibility compared to rigid PCB solutions. This embodiment, through the above design, addresses the shortcomings of traditional passive balancing technology while achieving a triple breakthrough in high current, low power consumption, and high integration, providing a low-cost, long-life balancing solution for high-capacity power battery systems.
[0032] Specifically, the resistor network PI heating element 14 is connected to the PCB body 10 via a wire 141 of the high-current balancing circuit. Thermally conductive double-sided adhesive is applied to the back of the resistor network PI heating element 14, which is connected to the side of the individual battery cell 20 via the adhesive. A heat dissipation system is provided at the bottom of the battery pack, and the resistor network PI heating element 14, folded and attached to the side of the individual battery cell 20, extends towards the heat dissipation system. Furthermore, while existing battery packs typically have a heat dissipation system at the bottom, in this embodiment, the individual battery cell 20 has folded resistor network PI heating elements 14 on both sides. When the resistor network PI heating elements 14 are attached to the side of the individual battery cell 20, the high-current balancing circuit extends towards the aforementioned heat dissipation system. Therefore, the heat dissipation effect is better on the side of the high-current balancing circuit closer to the heat dissipation system.
[0033] In a preferred embodiment, the serpentine network structure is configured as a non-uniform structure, that is, the smaller the line width or the narrower the spacing of the wide copper foil traces on the bottom side (the side closer to the heat dissipation system) of the serpentine network structure, the greater the local resistance and the higher the heat generation. Since this part of the wide copper foil traces is closer to the heat dissipation system, the overall heat dissipation effect of this non-uniform structure is better.
[0034] The technical solution provided in this application uniquely increases the passive balancing current from <1A in traditional solutions to 10A, achieving a balancing power of up to 32W for a single 2020 cell and increasing the balancing speed by more than 10 times. This meets the rapid balancing requirements of high-capacity battery packs. The distributed resistor circuit can be configured as a dual-side parallel serpentine resistor network, evenly distributing the 10A total current to both sides of the 2020 cell, with 5A on each side. Combined with 1.5mm wide copper foil traces, this ensures current carrying capacity and path balance, avoiding local overload. The wide copper foil serpentine resistor network increases the heat dissipation area several times, controlling the maximum temperature rise to ≤40℃, solving the problems of traditional centralized balancing. To prevent insulation failure or material aging caused by localized high temperatures, the equalization control chip is placed on the main control PCB and connected to the PCB body 10 via a high-speed communication interface. This avoids thermal interference from resistor heating to the chip and improves the stability of system parameters. This solution integrates the discrete power resistors, which are independently mounted on the BMU in existing technologies, onto the resistor network PI heating element 14. This highly integrates a complete equalization circuit within a limited space, including a distributed resistor network, MOSFET switch array, and voltage / temperature acquisition lines. This solves the technical problem of large space occupation and difficulty in adapting discrete high-power resistors to thin and light battery packs. The high-current equalization circuit and resistor network PI heating element 14 are independently foldable. Besides increasing the heat dissipation area, the folded high-current equalization circuit can be attached to both sides of the individual battery cell 20, making reasonable use of limited space and further enhancing the heat dissipation efficiency of the high-current equalization circuit by combining it with the heat dissipation structure of the individual battery cell 20. This invention, through a highly integrated high-current equalization circuit solution, improves passive equalization efficiency while solving the space limitations and thermal reliability bottlenecks of traditional solutions, providing a low-cost, mass-producible equalization solution for high-capacity power batteries.
[0035] Example 2 This embodiment provides a battery pack, which includes a high-current passive balancing battery management device based on PCB-CCS, comprising a PCB body 10 and at least one resistor network PI heating element 14; the PCB body 10 is provided with at least two signal acquisition units, each signal acquisition unit including a signal acquisition circuit, a nickel plate 11, and a switching circuit, each signal acquisition circuit being connected to one or a group of high-current balancing circuits, the high-current balancing circuit including a distributed resistor circuit, which serves as a parallel resistor for energy dissipation of a single battery cell 20; each high-current balancing circuit is disposed on one resistor network PI heating element 14, or multiple high-current balancing circuits are integrated on one resistor network PI heating element 14.
[0036] The battery pack provided in this application increases the passive balancing current from <1A in traditional solutions to 10A, with a single 2020 cell achieving a balancing power of up to 32W and a balancing speed more than 10 times faster. This meets the rapid balancing requirements of high-capacity battery packs. The distributed resistor circuit can be configured as a dual-sided parallel serpentine resistor network, evenly distributing the 10A total current to both sides of the 2020 cell, 5A on each side. Combined with 1.5mm wide copper foil traces, this ensures current carrying capacity and path balance, avoiding localized overload. The wide copper foil serpentine resistor network increases the heat dissipation area several times, controlling the maximum temperature rise to ≤40℃, thus solving the problem of localized overload in traditional centralized resistors. To address the issue of insulation failure or material aging caused by high temperatures, the equalization control chip is placed on the main control PCB and connected to the PCB body 10 via a high-speed communication interface. This avoids thermal interference from resistor heating, improving the stability of system parameters. This solution integrates the discrete power resistors, previously independently mounted on the BMU, onto the resistor network PI heating element 14. Within a limited space, a complete equalization circuit is highly integrated, including a distributed resistor network, MOSFET switch array, and voltage / temperature acquisition lines. This solves the technical challenge of large space requirements and difficulty in adapting discrete high-power resistors to thin and light battery packs. The high-current equalization circuit and resistor network PI heating element 14 are independently foldable. Besides increasing the heat dissipation area, the folded high-current equalization circuit can be attached to both sides of the individual battery cell 20, making reasonable use of limited space and further enhancing the heat dissipation efficiency of the high-current equalization circuit by combining it with the heat dissipation structure of the individual battery cell 20. This invention, through a highly integrated high-current equalization circuit solution, improves passive equalization efficiency while solving the space limitations and thermal reliability bottlenecks of traditional solutions, providing a low-cost, mass-producible equalization solution for high-capacity power batteries.
[0037] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this application's patent. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application.
[0038] It should be noted that when an element is referred to as being "fixed to" or "set on" another component, it can be directly or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly or indirectly connected to the other component. It should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.
[0040] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.
Claims
1. A high-current passive balancing battery management device based on PCB-CCS, characterized in that, Includes the PCB body and at least one resistor network PI heating element; The PCB body is provided with at least two signal acquisition units. Each signal acquisition unit includes a signal acquisition circuit, a nickel plate, and a switching circuit. Each signal acquisition circuit is connected to one or a group of high-current balancing circuits. The high-current balancing circuit includes a distributed resistor circuit, which serves as a parallel resistor for energy dissipation of a single battery cell. Each high-current balancing circuit is set on a resistor network PI heating element, or multiple high-current balancing circuits are integrated on a resistor network PI heating element.
2. The high-current passive balancing battery management device based on PCB-CCS according to claim 1, characterized in that, The positive or negative terminal of each individual cell is connected to the signal acquisition circuit via a nickel plate. When the voltage acquired by the signal acquisition circuit exceeds the preset threshold, the switching circuit connects the high-current balancing circuit connected in parallel to the individual cell to dissipate energy.
3. The high-current passive balancing battery management device based on PCB-CCS according to claim 1, characterized in that, One resistor network PI heating element is provided on each side of the PCB body. The PCB body is located on one side of the battery pack terminal. The high current balancing circuit of the PCB body connected to the first side battery pack is located on the resistor network PI heating element near the first side. The high current balancing circuit of the PCB body connected to the second side battery pack is located on the resistor network PI heating element near the second side.
4. The high-current passive balancing battery management device based on PCB-CCS according to claim 1, characterized in that, The signal acquisition unit also includes an NTC sensor, and multiple signal acquisition units are connected to an endplate connector located at one end of the PCB.
5. The high-current passive balancing battery management device based on PCB-CCS according to claim 1, characterized in that, The distributed resistance circuit is a wide copper foil trace or a heating film trace, and the distributed resistance circuit is either integrated with the signal acquisition circuit or connected separately.
6. The high-current passive balancing battery management device based on PCB-CCS according to claim 1, characterized in that, Each signal acquisition circuit is connected to two high-current equalization circuits. The two high-current equalization circuits and the resistor network PI heating element are independently arranged on both sides of the individual battery cell.
7. The high-current passive balancing battery management device based on PCB-CCS according to claim 1, characterized in that, The resistor network PI heating element is connected to the PCB body via wires from a high-current balancing circuit.
8. The high-current passive balancing battery management device based on PCB-CCS according to claim 7, characterized in that, The back of the resistor network PI heating element is provided with thermally conductive double-sided adhesive, and the resistor network PI heating element is connected to the side of the single cell through the thermally conductive double-sided adhesive.
9. The high-current passive balancing battery management device based on PCB-CCS according to claim 8, characterized in that, A heat dissipation system is installed at the bottom of the battery pack. When folded, the PI heating element of the resistor network attached to the side of the individual battery cell extends towards the heat dissipation system.
10. A battery pack, characterized in that, This includes any of the high-current passive balancing battery management devices based on PCB-CCS as described in claims 1-9.