Dynamic battery charge balancing apparatus and method and rechargeable battery device

Abstract

The present invention discloses a dynamic battery charge balancing device, which is applied to a multi-cell battery pack including a plurality of battery cells and a battery management circuit. According to the design of the present invention, the dynamic battery charge balancing device monitors a plurality of battery voltages of the plurality of battery cells, and generates a plurality of balancing charging currents to charge the plurality of battery cells respectively in case that a battery voltage difference between any two of the battery cells exceeds a preset threshold. It is worth mentioning that each of the balancing charging currents is calculated by taking (remaining) chargeable time, current battery voltage of each of the battery cells and a rated battery capacity as parameters. Therefore, in a charging cycle, the balancing charging current used to charge the battery cell with low battery voltage is greater than the balancing charging current used to charge the battery cell with high battery voltage. According to the design, the dynamic battery charge balancing device of the present invention can quickly balance (eliminate) the battery voltage difference between any two of the battery cells, and ultimately eliminate the phenomenon of battery voltage imbalance between any two of the battery cells.

Description

Technical Field

[0001] This invention relates to the technical field of multi-cell battery packs, and more particularly to a dynamic battery charging balancing device and method. Background Technology

[0002] With the continuous emergence of new cordless high-power electrical products (such as cordless vacuum cleaners, power tools, and robotic vacuum cleaners), multi-cell battery packs containing multiple battery units have become widely used. Figure 1 This displays a 3D diagram of a conventional multi-cell battery pack. For example... Figure 1 As shown, the basic components of a conventional multi-cell battery pack 1a include: multiple battery cells 11a, multiple battery holders 12a, and a battery management circuit 13a. In practice, the multi-cell battery pack 1a is usually housed in a specially designed housing, thereby forming a rechargeable battery device with the housing, which is convenient for assembly into an electrical appliance body (such as the main body of a cordless vacuum cleaner).

[0003] It should be understood that, in addition to high-power wireless electrical products, multi-cell battery packs 1a are also used in the manufacture of battery systems for new energy vehicles such as electric motorcycles and electric vehicles. When the rechargeable battery device containing the multi-cell battery pack 1a is low on power or depleted, it must be charged using a charging device. During charging, the charging device charges each battery cell 11a within the multi-cell battery pack 1a with a constant current until the battery voltage of each battery cell 11a reaches a target battery voltage. Unfortunately, there are fundamental differences between the individual battery cells 11a. Therefore, even if the indicator light shows that the rechargeable battery device is fully charged, the individual battery cells 11a within the multi-cell battery pack 1a cannot have the same capacity. On the other hand, even with a fixed charging and discharging current, the individual battery cells 11a will not have the same charging and discharging efficiency.

[0004] Practical experience indicates that lithium-ion battery cells 11a have high rated voltage (3.4–4.2 volts) and energy density. Therefore, a high-voltage and high-capacity multi-cell battery pack 1a can be easily achieved by connecting a small number of lithium-ion battery cells 11a in series. However, lithium-ion battery cells 11a have some drawbacks, such as over-discharge causing battery cell imbalance, resulting in unequal battery capacities (or battery voltages) between different battery cells 11a in the multi-cell battery pack 1a. Therefore, in addition to sending the charging current provided by the charging device to each battery cell 11a and receiving the discharge current of each battery cell 11a, the battery management circuit 13a is also used to provide overcharge protection, over-discharge protection, overcurrent protection, and short-circuit protection to each battery cell 11a.

[0005] Under the protection of battery management circuit 13a, battery cells 11a with high battery voltage will quickly reach the high voltage protection voltage when the multi-cell battery pack 1a is charging, thereby activating overcharge protection to stop charging. Conversely, when the multi-cell battery pack 1a is discharging, battery cells 11a with low battery voltage will easily reach the low voltage protection voltage, thereby activating over-discharge protection to stop discharging. Therefore, the imbalance of battery cells 11a will shorten the rechargeable time and / or endurance of the multi-cell battery pack 1a, which is the main reason for the increasingly poor battery life of rechargeable battery devices with this multi-cell battery pack 1a.

[0006] To improve the aforementioned deficiencies, the power management circuit 13a must possess a battery cell balancing function to address the battery cell imbalance problem in the multi-cell battery pack 1a. US Patent No. 8,035,343 discloses a method for balancing battery cells in a multi-cell battery pack. According to the disclosure of US Patent No. 8,035,343, a monitoring and balancing circuit comprising multiple sub-monitoring and balancing units is integrated into a battery management circuit 13a (see reference). Figure 1 Furthermore, each of the multiple sub-monitoring and balancing units is coupled to a battery cell 11a (see reference). Figure 1 During discharge, the monitoring and balancing circuit monitors only the battery voltage of each battery cell 11a. However, during charging, the monitoring and balancing circuit monitors and balances the battery voltage of each battery cell 11a.

[0007] To explain in more detail, during charging, the charging device first outputs its maximum charging current (e.g., 450mA). The monitoring and balancing circuit uses this maximum charging current as a first charging current to charge each battery cell 11a of the multi-cell battery pack 1a. Next, the monitoring and balancing circuit measures the battery voltage of each battery cell 11a. When the battery voltage of at least one battery cell 11a reaches a target battery voltage (e.g., 3.6V), the first charging current is reduced by a predetermined amount to become a second charging current. Then, each battery cell 11a of the multi-cell battery pack 1a is charged with the second charging current, and when at least one battery cell 11a is charged to have a target battery voltage, the first charging current is reduced by a predetermined amount to become a third charging current. This process continues until the charging current used to charge the battery cell 11a is reduced to a minimum charging current of the charging device (e.g., 45mA or 140mA).

[0008] In short, the method for balancing battery cells in a battery pack proposed in US Patent No. 8,035,343 requires multiple charging cycles to balance the battery voltage of the multiple battery cells 11a in a multi-cell battery pack 1a containing multiple battery cells 11a. As shown in Table (1) below, when using the conventional method for balancing battery cells to balance the battery voltage of a multi-cell battery pack of Samsung ICR18650-22P, it was found that at least 8 charging cycles were required to balance the battery voltage of the battery cells. Therefore, it can be inferred that the greater the difference between the maximum and minimum battery voltage of the multiple battery cells 11a in the multi-cell battery pack 1a, the greater the total number of charging cycles will be. It should be noted that Table (1) below shows the highest and lowest battery voltages at the start of charging, and charging to a voltage of 4.25V for any battery cell is considered fully charged.

[0009] Table (1)

[0010]

[0011] It should be noted that commercially available battery management circuit 13a (reference) Figure 1The charging device and / or charging equipment usually also have a charging time protection function, which stops charging after the charging time exceeds a charging time threshold (e.g., 6 to 12 hours, depending on the charging current). However, as can be seen from Table (1), the charging time consumed in the first and second charging cycles of the multi-cell battery pack of Samsung ICR18650-22P is 1.35 hours and 2.86 hours, respectively, which is far lower than the charging time threshold. It is clear that the conventional method of balancing battery cells only considers battery voltage and charging current, and does not take the maximum rechargeable time into account at the same time.

[0012] As can be seen from the foregoing description, there is still room for improvement in conventional methods of balancing battery cells. In view of this, the inventors of this case have made great efforts to research and invent, and have finally developed a dynamic battery charging balancing device and method. Summary of the Invention

[0013] The main objective of this invention is to provide a dynamic battery charging balancing device for use in a multi-cell battery pack comprising multiple battery cells and a battery management circuit. According to the design of this invention, the dynamic battery charging balancing device monitors multiple battery voltages of the multiple battery cells, and generates multiple balancing charging currents to charge the multiple battery cells respectively when the voltage difference between any two battery cells exceeds a preset threshold. It is worth noting that each balancing charging current is calculated using parameters such as (remaining) rechargeable time, the current battery voltage of each battery cell, and a rated battery capacity. Therefore, in a charging cycle, the balancing charging current used to charge the battery cell with the lower voltage will be greater than the balancing charging current used to charge the battery cell with the higher voltage, and the charging current is dynamically adjusted to delay the battery reaching a maximum voltage of 4.25V for full charge. With this design, the dynamic battery charging balancing device of this invention can quickly balance (eliminate) the voltage difference between any two battery cells, ultimately eliminating the phenomenon of voltage imbalance between any two battery cells.

[0014] To achieve the above objectives, the present invention provides an embodiment of the dynamic battery charging balancing device, which is applied to a multi-cell battery pack comprising multiple battery cells and a battery management circuit, wherein the battery management circuit has a control unit, and the dynamic battery charging balancing device is integrated into the battery management circuit; the dynamic battery charging balancing device includes:

[0015] A battery voltage sensing unit, coupled to the plurality of battery cells, is used to perform battery voltage sensing on each of the battery cells, thereby outputting a plurality of voltage sensing signals; and

[0016] A battery balancing control module, coupled to the battery voltage sensing unit and the control unit, and includes:

[0017] A first signal processing unit receives the plurality of voltage sensing signals from the battery voltage sensing unit and converts the plurality of voltage sensing signals into a plurality of battery voltage signals; and

[0018] A balance control unit is coupled to the first signal processing unit to receive the plurality of battery voltage signals, thereby determining the plurality of battery voltages corresponding to the plurality of battery cells based on each of the battery voltage signals;

[0019] The balance control unit calculates multiple balance charging currents based on a rechargeable time, a target battery voltage, multiple battery voltages, and a rated capacity of the battery cells, and then controls the control unit to charge the multiple battery cells with the multiple balance charging currents respectively.

[0020] In one embodiment, the dynamic battery charging balancing device of the present invention further includes:

[0021] A charging current sensing unit, coupled to the control unit, is used to sense a charging current transmitted by the control unit to each of the battery cells.

[0022] In one embodiment, the battery balance control module further includes:

[0023] A second signal processing unit, coupled to the charging current sensing unit, receives a current sensing signal and converts the current sensing signal into a charging current signal; wherein the balance control unit is also coupled to the second signal processing unit, thereby receiving the charging current signal and determining, based on the charging current signal, the charging current transmitted by the control unit to each of the battery cells; and

[0024] A time counter, coupled to the balance control unit, is used to count the charging time of the battery cell, thereby outputting a time count signal to the balance control unit; wherein the balance control unit calculates the rechargeable time based on a charging time threshold and the time count signal.

[0025] In a feasible embodiment, the battery balance control module further includes:

[0026] A parameter storage unit, coupled to the balance control unit, is used to store multiple setting parameters, including: the charging time threshold, the target battery voltage, and the rated capacity.

[0027] In one embodiment, the balance control unit calculates the balance charging current using the following mathematical formula (I):

[0028]

[0029] Where K is a proportionality coefficient, I B For the balanced charging current, B C For the rated capacity, V target V is the target battery voltage. cell The battery voltage is T. C The rechargeable time is [the specified time].

[0030] In another embodiment, the balance control unit calculates the balance charging current using the following mathematical formula (II):

[0031]

[0032] Where K is a proportionality coefficient, I B For the balanced charging current, B C For the rated capacity, V target V is the target battery voltage. cell The battery voltage is T. C The rechargeable time is [the specified time].

[0033] In a feasible embodiment, the battery management circuit also includes a temperature sensing unit, an overcharge protection unit, an over-discharge protection unit, an overcurrent protection unit, a short circuit protection unit, and a charging time protection unit.

[0034] In one embodiment, if the calculated balancing charging current is greater than a maximum charging current of a charging device, the balancing control unit corrects the balancing charging current to the maximum charging current. Furthermore, if the calculated balancing charging current is lower than a minimum charging current of a charging device, the balancing control unit corrects the balancing charging current to the minimum charging current.

[0035] This invention also discloses a dynamic battery balancing method, which is implemented using a battery balancing control module. A multi-cell battery pack includes multiple battery cells and a battery management circuit, and the battery balancing control module is integrated into the battery management circuit. The dynamic battery balancing method includes the following steps:

[0036] (1) Perform battery voltage monitoring on the multiple battery cells to obtain the voltage of multiple batteries;

[0037] (2) If the voltage difference between any two battery voltages is greater than an upper threshold value, start the battery voltage balancing process for the plurality of battery cells.

[0038] (3) Calculate multiple balancing charging currents based on a rechargeable time, a target battery voltage, multiple battery voltages, and a rated capacity of the battery cells, and then control the control unit to charge the multiple battery cells with the multiple balancing charging currents respectively; and

[0039] (4) Repeat steps (1), (2) and (3) until the voltage difference of each battery is equal to or less than a low threshold value, then stop the battery voltage balancing process.

[0040] Furthermore, the present invention also discloses a rechargeable battery device, comprising: a multi-cell battery pack consisting of multiple battery cells and a battery management circuit; characterized in that the battery management circuit further integrates a battery balance control module for implementing the dynamic battery balancing method of the present invention as described above. Attached Figure Description

[0041] Figure 1 A three-dimensional diagram of a known multi-cell battery pack;

[0042] Figure 2 A three-dimensional diagram of a wireless device;

[0043] Figure 3 for Figure 2 A perspective view of a multi-cell battery pack included in a rechargeable battery device for a wireless device;

[0044] Figure 4 This is a block diagram of a dynamic battery charging balancing device according to the present invention;

[0045] Figure 5 A three-dimensional surface diagram drawn based on the data contained in Table (2);

[0046] Figure 6 A three-dimensional surface diagram drawn based on the data contained in Table (3); and

[0047] Figure 7 This is a flowchart of a dynamic battery balancing method according to the present invention.

[0048] [Symbol Explanation]

[0049] <Invention>

[0050] 1: Multi-cell battery pack

[0051] 11: Battery Unit

[0052] 12: Battery holder

[0053] 13: Battery Management Circuit

[0054] 131: Control Unit

[0055] 132: Battery voltage sensing unit

[0056] 133: Charging current sensing unit

[0057] 134: Battery Balance Control Module

[0058] 1340: Balance Control Unit

[0059] 1341: First Signal Processing Unit

[0060] 1342: Second Signal Processing Unit

[0061] 1343: Parameter storage unit

[0062] 1344: Time Counter

[0063] 3: Wireless equipment

[0064] 31: Body

[0065] 32: Rechargeable battery device

[0066] 33: Charging device

[0067] S1-S4: Steps

[0068] <Knowledge>

[0069] 1a: Multi-cell battery pack

[0070] 11a: Battery cell

[0071] 12a: Battery holder

[0072] 13a: Battery Management Circuit Detailed Implementation

[0073] To more clearly describe the dynamic battery charging balancing device and method, as well as the rechargeable battery device proposed in this invention, the preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings.

[0074] Please see Figure 2 It displays a 3D image of a cordless appliance. For example... Figure 2 As shown, the wireless device 3 is a power tool, which includes a body 31, a rechargeable battery device 32, and a charging device 33. Furthermore, Figure 3 show Figure 2 A perspective view of the rechargeable battery device 32 of the wireless device 3, comprising a multi-cell battery pack 1. It should be understood that the multi-cell battery pack 1 is typically housed within a specially designed housing, thereby forming a configuration similar to... Figure 2The rechargeable battery device 32 shown is designed to facilitate assembly into the body 31. Of course, in addition to wireless high-power electrical products, the multi-cell battery pack 1 can also be used in electric motorcycles, electric vehicles, or high-capacity mobile power supplies.

[0075] like Figure 3 As shown, the basic components of the multi-cell battery pack 1 include: multiple battery cells 11, multiple battery holders 12, and a battery management circuit 13. It is worth noting that the dynamic battery charging balancing device proposed in this invention is integrated into the battery management circuit 13. Figure 4 This shows a block diagram of a dynamic battery charging balancing device according to the present invention. Figure 3 and Figure 4 It is known that the battery management circuit 13 has a (charge / discharge) control unit 131, and the dynamic battery charging balance device of the present invention includes: a battery voltage sensing unit 132, a charging current sensing unit 133, and a battery balance control module 134, wherein the battery voltage sensing unit 132 is coupled to the plurality of battery cells 11 to perform a battery voltage sensing on each of the battery cells 11, thereby outputting a plurality of voltage sensing signals.

[0076] It should be understood that when the rechargeable battery device 32 containing the multi-cell battery pack 1 is low on power or depleted, it must be charged using the charging device 33. During charging, the (charge / discharge) control unit 131 of the battery management circuit 13 uses a constant current provided by the charging device 33 to charge each battery cell 11 within the multi-cell battery pack 1. Therefore, the present invention couples the charging current sensing unit 133 to the control unit 131 to sense a charging current transmitted by the control unit 131 to each of the battery cells 11. Simultaneously, the battery voltage sensing unit 132 is coupled to the multiple battery cells 11 to perform battery voltage sensing on each of the battery cells 11, thereby outputting multiple voltage sensing signals.

[0077] like Figure 3 and Figure 4As shown, the battery balance control module 134 is coupled to the control unit 131, the battery voltage sensing unit 132, and the charging current sensing unit 133, and includes: a first signal processing unit 1341, a second signal processing unit 1342, a parameter storage unit 1343, and a balance control unit 1340. The first signal processing unit 1341 receives multiple voltage sensing signals from the battery voltage sensing unit 132 and converts these signals into multiple battery voltage signals. Conversely, the second signal processing unit 1342 receives a current sensing signal from the charging current sensing unit 133, providing the second signal processing unit 1342 and the control unit 131 with monitoring and feedback control of the charging current magnitude. In more detail, the balance control unit 1340 is coupled to the first signal processing unit 1341 and the second signal processing unit 1342 to receive the plurality of battery voltage signals and the charging current signal, thereby knowing the plurality of battery voltages based on the plurality of battery voltage signals, and knowing the charging current transmitted by the control unit 131 to each of the battery cells 11 based on the charging current signal.

[0078] According to the design of this invention, the balance control unit 1340 initiates a battery voltage balancing process for the plurality of battery cells 11 when the voltage difference between any two battery voltages exceeds an upper threshold. Furthermore, the balance control unit 1340 must perform multiple charging cycles on each of the battery cells 11 to complete the battery voltage balancing process. In each charging cycle, the balance control unit 1340 calculates multiple balancing charging currents based on a (remaining) rechargeable time, a target battery voltage, the plurality of battery voltages, and a rated capacity of the battery cell 11, and then controls the control unit 131 to charge the plurality of battery cells 11 with the multiple balancing charging currents respectively.

[0079] It should be understood that the battery management circuit 13 typically includes functions such as temperature sensing, overcharge protection, over-discharge protection, overcurrent protection, short circuit protection, and charging time protection. Specifically, the charging time protection is used to stop the control unit 131 from transmitting charging current to each of the battery cells 11 after the charging time exceeds a charging time threshold (e.g., 7 hours, depending on the charging current). Therefore, it can be understood that the (remaining) rechargeable time is the difference between the charging time threshold and the time already spent charging. Therefore, to calculate the rechargeable time, as... Figure 4As shown, the battery balance control module 134 also includes a time counter 1344 coupled to the balance control unit 1340, which is used to count the charging time of the battery cell 11. In other words, when the charging device 33 starts charging the rechargeable battery device 32 containing the multi-cell battery pack 1, the time counter 1344 starts counting the charging time, thereby knowing the charging time.

[0080] And, as Figure 4 As shown, the parameter storage unit 1343 is coupled to the balancing control unit 1340 and stores multiple setting parameters, including the charging time threshold, the target battery voltage, and the rated capacity. With this design, before starting the battery voltage balancing process for the multiple battery cells 11, the balancing control unit 1340 receives a time counting signal transmitted from the time counter 1344, thereby determining the charging time from the time counting signal. Then, based on the charging time threshold (e.g., 7 hours) and the charging time already performed, it calculates the (remaining) rechargeable time. Finally, the balancing control unit 1340 further calculates multiple balancing charging currents based on the calculated rechargeable time, the target battery voltage, the multiple battery voltages, and the rated capacity of the battery cells 11, and then controls the control unit 131 to charge the multiple battery cells 11 with the multiple balancing charging currents in a charging cycle.

[0081] In more detail, the balance control unit 1340 calculates the balance charging current using the following mathematical formula (I) or (II):

[0082]

[0083]

[0084] In equations (I) and (II) above, K is a proportionality coefficient, and I B For the balanced charging current, B C For the rated capacity, V target V is the target battery voltage. cell The battery voltage is T. CThe rechargeable time is specified. It should be further noted that during each charging cycle, the balance control unit 1340 calculates multiple balance charging currents using equation (I) or (II) above, and then controls the control unit 131 to charge the multiple battery cells 11 using these multiple balance charging currents respectively. It is worth noting that if the calculated balance charging current is greater than a maximum charging current of the charging device 33 (e.g., 450mA), the balance control unit 1340 corrects the balance charging current to the maximum charging current. Furthermore, if the calculated balance charging current is lower than a minimum charging current of the charging device 33 (e.g., 45mA or 140mA), the balance control unit 1340 corrects the balance charging current to the minimum charging current.

[0085] For example, if the target battery voltage is 4.3V, the maximum charging current is 450mA, the minimum charging current is 45mA, and the battery cell 11 is an 18650 lithium-ion battery with a rated capacity of 2200mA / h, then the corresponding balance charging current can be calculated using the above formula (I) based on different (remaining) rechargeable times and different battery voltages, and summarized as shown in Table (2) below.

[0086] Table (2)

[0087] 6 hrs 5 hrs 4 hrs 3 hours 2 hrs 1 hr 3.2V 403.3mA 450.0mA 450.0mA 450.0mA 450.0mA 450.0mA 3.3V 366.7mA 440.0mA 450.0mA 450.0mA 450.0mA 450.0mA 3.4V 330.0mA 396.0mA 450.0mA 450.0mA 450.0mA 450.0mA 3.5V 293.3mA 352.0mA 440.0mA 450.0mA 450.0mA 450.0mA 3.6V 256.7mA 308.0mA 385.0mA 450.0mA 450.0mA 450.0mA 3.7V 220.0mA 264.0mA 330.0mA 440.0mA 450.0mA 450.0mA 3.8V 183.3mA 220.0mA 275.0mA 366.7mA 450.0mA 450.0mA 3.9V 146.7mA 176.0mA 220.0mA 293.3mA 440.0mA 450.0mA 4.0V 110.0mA 132.0mA 165.0mA 220.0mA 330.0mA 450.0mA 4.1V 73.3mA 88.0mA 110.0mA 146.7mA 220.0mA 440.0mA 4.2V 45.0mA 45.0mA 55.0mA 73.3mA 110.0mA 220.0mA

[0088] Figure 5 Display the three-dimensional surface plot drawn based on the data in Table (2). Figure 5 It can be observed that the balancing charging current calculated using the above formula (I) is simultaneously related to the battery voltage and (remaining) rechargeable time monitored for each battery cell 11. Therefore, assuming that the duration of each charging cycle is 1 hour, the same battery cell 11 will have different balancing charging currents in different charging cycles. In other words, the balancing charging current used by the dynamic battery charging balancing device of the present invention to charge each battery cell 11 changes dynamically in different charging cycles. Furthermore, it can be found from the data in Table (2) above that in each charging cycle, the balancing charging current used to charge the battery cell 11 with a low battery voltage is greater than the balancing charging current used to charge the battery cell 11 with a high battery voltage. Based on this design, the dynamic battery charging balancing device of the present invention can quickly balance (eliminate) the battery voltage difference between any two battery cells 11, and ultimately eliminate the phenomenon of battery voltage imbalance between any two battery cells 11.

[0089] On the other hand, if the target battery voltage is 4.3V, the maximum charging current is 450mA, the minimum charging current is 140mA, and the battery cell 11 is an 18650 lithium-ion battery with a rated capacity of 2200mA / h, then the corresponding balanced charging current can be calculated using the above formula (II) based on different rechargeable times and different battery voltages, and summarized in the following table (3).

[0090] Table (3)

[0091] 6 hrs 5 hrs 4 hrs 3 hours 2 hrs 1 hr 3.2V 450mA 450.0mA 450.0mA 450.0mA 450.0mA 450.0mA 3.3V 449.1Ma 450.0mA 450.0mA 450.0mA 450.0mA 450.0mA 3.4V 429.0mA 450.0mA 450.0mA 450.0mA 450.0mA 450.0mA 3.5V 401.7mA 440.0mA 450.0mA 450.0mA 450.0mA 450.0mA 3.6V 375.7mA 411.6mA 450.0mA 450.0mA 450.0mA 450.0mA 3.7V 347.9mA 381.1mA 426.0mA 450.0mA 450.0mA 450.0mA 3.8V 317.5mA 347.9mA 388.9mA 449.1mA 450.0mA 450.0mA 3.9V 284.0mA 311.1mA 347.9mA 401.7mA 450.0mA 450.0mA 4.0V 246.0mA 269.4mA 301.2mA 347.9mA 426.0mA 450.0mA 4.1V 200.8mA 220.0mA 246.0mA 284.0mA 347.9mA 450.0mA 4.2V 142.0mA 155.6mA 173.9mA 200.8mA 246.0mA 347.9mA

[0092] Figure 5 Display the three-dimensional surface plot drawn based on the data in Table (3). Figure 6 It can be observed that the balancing charging current calculated using equation (II) above is simultaneously related to the battery voltage and (remaining) rechargeable time monitored for each battery cell 11. Therefore, assuming each charging cycle lasts for 1 hour, the same battery cell 11 will have different balancing charging currents in different charging cycles. In other words, the balancing charging current used by the dynamic battery charging balancing device of the present invention to charge each battery cell 11 changes dynamically in different charging cycles.

[0093] Thus, the above description clearly discloses the components and applications of a dynamic battery charging balancing device according to the present invention. Furthermore, the present invention also discloses a dynamic battery balancing method, which utilizes a battery balancing control module 134 (such as...). Figure 3 , Figure 4 As shown in the figure. Figure 7 This diagram shows a flowchart of a dynamic battery balancing method according to the present invention. Figure 7 As shown, the dynamic battery balancing method of the present invention includes four main steps. First, as... Figure 3 , Figure 4 and Figure 7 As shown, the method flow is as follows: Step S1: Monitor the battery voltage of the plurality of battery cells 11 to obtain the plurality of battery voltages. Next, the method flow is as follows: Step S2: If the difference between any two of the battery voltages is greater than an upper threshold of battery cell voltage difference, start the battery voltage balancing process for the plurality of battery cells 11.

[0094] like Figure 3 , Figure 4 and Figure 7As shown, the method flow proceeds to step S3: based on a (remaining) rechargeable time, a target battery voltage (e.g., 4.3V), multiple battery voltages, and a rated capacity of the battery cell 11 (e.g., 2200mA / h), multiple balancing charging currents are calculated, and then the control unit 131 is controlled to charge the multiple battery cells 11 with the multiple balancing charging currents respectively. After completing one charging cycle, the method steps continue to execute step S4: repeating steps S1, S2, and S3 until the battery voltage difference is equal to or less than a lower threshold of battery cell voltage difference, at which point the battery voltage balancing process is stopped. In other words, when executing step S4, the dynamic battery charging balancing device of the present invention (e.g., Figure 3 and Figure 4 As shown, the battery voltage of the multiple battery cells 11 will be monitored repeatedly, and if the voltage difference between any two battery cells is greater than the upper threshold, a new balance charging current will be calculated, and a charging cycle will be performed again.

[0095] As shown in Table (4) below, the battery voltage balancing process of the multi-cell battery pack of Samsung ICR18650-22P was performed using the dynamic battery balancing method of the present invention. It was found that only 6 charging cycles were needed to complete the battery voltage balancing process for the multiple battery cells 11.

[0096] Table (4)

[0097]

[0098] Thus, the foregoing has fully and clearly described a dynamic battery charging balancing device and method, as well as a rechargeable battery device, according to the present invention. It must be emphasized that the above detailed description is a specific description of feasible embodiments of the present invention, but these embodiments are not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the spirit of the present invention should be included within the patent scope of this case.

Claims

1. A dynamic battery charging balancing device, applied in a multi-cell battery pack comprising multiple battery cells and a battery management circuit, characterized in that, The battery management circuit has a control unit, and the dynamic battery charge balancing device is integrated into the battery management circuit; the dynamic battery charge balancing device includes: A battery voltage sensing unit, coupled to the plurality of battery cells, is used to perform battery voltage sensing on each of the battery cells, thereby outputting a plurality of voltage sensing signals; and A battery balancing control module, coupled to the battery voltage sensing unit and the control unit, and includes: A first signal processing unit receives the plurality of voltage sensing signals from the battery voltage sensing unit and converts the plurality of voltage sensing signals into a plurality of battery voltage signals; A balance control unit, coupled to the first signal processing unit, receives the plurality of battery voltage signals, thereby determining, based on each of the battery voltage signals, the plurality of battery voltages corresponding to the plurality of battery cells; and A time counter, coupled to the balance control unit, is used to count the charging time of the battery cell, thereby outputting a time count signal to the balance control unit. The balance control unit calculates a rechargeable time based on a charging time threshold and the time counting signal. The balance control unit calculates multiple balance charging currents based on a rechargeable time, a target battery voltage, multiple battery voltages, and a rated capacity of the battery cell, and then controls the control unit to charge the multiple battery cells with the multiple balance charging currents respectively. Where the calculated balance charging current is greater than a maximum charging current of a charging device, the battery balance control module corrects the balance charging current to the maximum charging current. The balance control unit calculates the balance charging current using the following mathematical formula (I): Where K is a proportionality coefficient. For the balanced charging current, For the rated capacity, The target battery voltage, The battery voltage is, and The rechargeable time is [the specified time].

2. A dynamic battery charging balancing device, applied in a multi-cell battery pack comprising multiple battery cells and a battery management circuit, characterized in that, The battery management circuit has a control unit, and the dynamic battery charge balancing device is integrated into the battery management circuit; the dynamic battery charge balancing device includes: A battery voltage sensing unit, coupled to the plurality of battery cells, is used to perform battery voltage sensing on each of the battery cells, thereby outputting a plurality of voltage sensing signals; and A battery balancing control module, coupled to the battery voltage sensing unit and the control unit, and includes: A first signal processing unit receives the plurality of voltage sensing signals from the battery voltage sensing unit and converts the plurality of voltage sensing signals into a plurality of battery voltage signals; A balance control unit, coupled to the first signal processing unit, receives the plurality of battery voltage signals, thereby determining, based on each of the battery voltage signals, the plurality of battery voltages corresponding to the plurality of battery cells; and A time counter, coupled to the balance control unit, is used to count the charging time of the battery cell, thereby outputting a time count signal to the balance control unit. The balance control unit calculates a rechargeable time based on a charging time threshold and the time counting signal. The balance control unit calculates multiple balance charging currents based on a rechargeable time, a target battery voltage, multiple battery voltages, and a rated capacity of the battery cell, and then controls the control unit to charge the multiple battery cells with the multiple balance charging currents respectively. Where the calculated balance charging current is greater than a maximum charging current of a charging device, the battery balance control module corrects the balance charging current to the maximum charging current. The balance control unit calculates the balance charging current using the following mathematical formula (II): Where K is a proportionality coefficient. For the balanced charging current, For the rated capacity, The target battery voltage, The battery voltage is, and The rechargeable time is [the specified time].

3. The dynamic battery charging balancing device as described in claim 1 or 2, characterized in that, The battery balance control module also includes: A charging current sensing unit, coupled to the control unit, is used to sense a charging current transmitted by the control unit to each of the battery cells; A second signal processing unit is coupled to the charging current sensing unit to receive a current sensing signal and convert the current sensing signal into a charging current signal; wherein the balance control unit is also coupled to the second signal processing unit to receive the charging current signal and thereby know the charging current transmitted by the control unit to each of the battery cells based on the charging current signal.

4. The dynamic battery charging balancing device as described in claim 3, characterized in that, The battery balance control module also includes: A parameter storage unit, coupled to the balance control unit, is used to store multiple setting parameters, including: the charging time threshold, the target battery voltage, and the rated capacity.

5. The dynamic battery charging balancing device as described in claim 4, characterized in that, The battery management circuit also includes a temperature sensing unit, an overcharge protection unit, an over-discharge protection unit, an overcurrent protection unit, a short circuit protection unit, and a charging time protection unit.

6. The dynamic battery charging balancing device as described in claim 4, characterized in that, If the calculated balancing charging current is lower than a minimum charging current of a charging device, the balancing control unit corrects the balancing charging current to the minimum charging current.

7. A dynamic battery balancing method, characterized in that, It is implemented using a battery balancing control module, wherein a multi-cell battery pack includes multiple battery cells and a battery management circuit, and the battery balancing control module is integrated into the battery management circuit; the dynamic battery balancing method includes the following steps: (1) Perform battery voltage monitoring on the multiple battery cells to obtain the voltage of multiple batteries; (2) If the voltage difference between any two battery voltages is greater than an upper threshold value, start the battery voltage balancing process for the plurality of battery cells. (3) Calculate multiple balancing charging currents based on a rechargeable time, a target battery voltage, multiple battery voltages, and a rated capacity of the battery cells, and then control the control unit to charge the multiple battery cells respectively with the multiple balancing charging currents; and (4) Repeat steps (1), (2) and (3) until the voltage difference of each battery is equal to or less than a low threshold value, then stop the battery voltage balancing process. The battery balance control module calculates the balance charging current using the following mathematical formula (I): Where K is a proportionality coefficient. For the balanced charging current, For the rated capacity, The target battery voltage, The battery voltage is, and The rechargeable time is [the specified time].

8. A dynamic battery balancing method, characterized in that, It is implemented using a battery balancing control module, wherein a multi-cell battery pack includes multiple battery cells and a battery management circuit, and the battery balancing control module is integrated into the battery management circuit; the dynamic battery balancing method includes the following steps: (1) Perform battery voltage monitoring on the multiple battery cells to obtain the voltage of multiple batteries; (2) If the voltage difference between any two battery voltages is greater than an upper threshold value, start the battery voltage balancing process for the plurality of battery cells. (3) Calculate multiple balancing charging currents based on a rechargeable time, a target battery voltage, multiple battery voltages, and a rated capacity of the battery cells, and then control the control unit to charge the multiple battery cells respectively with the multiple balancing charging currents; and (4) Repeat steps (1), (2) and (3) until the voltage difference of each battery is equal to or less than a low threshold value, then stop the battery voltage balancing process. The battery balance control module calculates the balance charging current using the following mathematical formula (II): Where K is a proportionality coefficient. For the balanced charging current, For the rated capacity, The target battery voltage, The battery voltage is, and The rechargeable time is [the specified time].

9. The dynamic battery balancing method as described in claim 7 or 8, characterized in that, The battery balance control module includes: A first signal processing unit performs battery voltage sensing using a battery voltage sensing unit, thereby receiving multiple voltage sensing signals and converting the multiple voltage sensing signals into multiple battery voltage signals. A second signal processing unit uses a charging current sensing unit to perform a charging current sensing on a control unit of the battery management circuit, thereby receiving a current sensing signal from the charging current sensing unit and converting the current sensing signal into a charging current signal. A balance control unit is coupled to the first signal processing unit and the second signal processing unit to receive the plurality of battery voltage signals and the charging current signal, thereby knowing the plurality of battery voltages based on the plurality of battery voltage signals, and knowing a charging current transmitted by the control unit to each of the battery cells based on the charging current signal; A parameter storage unit, coupled to the balance control unit, is used to store multiple set parameters, including: a charging time threshold, the target battery voltage, and the rated capacity; and A time counter, coupled to the balance control unit, is used to count the charging time of the battery cell, thereby outputting a time count signal to the balance control unit, so that the balance control unit can calculate the rechargeable time based on the charging time threshold and the time count signal.

10. The dynamic battery balancing method as described in claim 9, characterized in that, The battery management circuit also includes a temperature sensing unit, an overcharge protection unit, an over-discharge protection unit, an overcurrent protection unit, a short circuit protection unit, and a charging time protection unit.

11. The dynamic battery balancing method as described in claim 9, characterized in that, If the calculated balancing charging current is greater than a maximum charging current of a charging device, the battery balancing control module will correct the balancing charging current to the maximum charging current.

12. The dynamic battery balancing method as described in claim 9, characterized in that, If the calculated balancing charging current is lower than a minimum charging current of a charging device, the battery balancing control module will correct the balancing charging current to the minimum charging current.

13. A rechargeable battery device, characterized in that, It includes: A multi-cell battery pack consisting of multiple battery cells and a battery management circuit; characterized in that the battery management circuit further integrates a battery balance control module for implementing the dynamic battery balancing method as described in any one of claims 7 or 8.

14. The rechargeable battery device as claimed in claim 13, characterized in that, This rechargeable battery device is used in a wireless device, an electric motor vehicle, an electric vehicle, or a high-capacity mobile power source.

Images