Cell balancing circuits, battery packs and power devices for battery packs

Abstract

The present disclosure relates to a battery equalization circuit, a battery pack and an electric energy device for a battery pack, wherein the battery equalization circuit for a battery pack comprises a control circuit and a plurality of passive equalization circuits, wherein the plurality of passive equalization circuits correspond one to one with the plurality of batteries, and the two ends of the passive equalization circuit are respectively connected to the positive and negative electrodes of the corresponding batteries; the control circuit is configured to determine the first equalization current value of the battery in use according to the equalization time of the battery in a first setting window and the use time of the battery in a second setting window when the set parameter value of the battery is greater than the set threshold; the control circuit is also configured to output a first discharge control signal corresponding to the first equalization current value to the passive equalization circuit corresponding to the battery; wherein the first discharge control signal causes the battery to discharge at the first equalization current value through the corresponding equalization discharge circuit. The present invention can reduce the temperature during battery equalization.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to the technical field of battery packs, and more particularly, to a battery balancing circuit for a battery pack, a battery pack, and an electric energy device. Background Art

[0002] Batteries are usually connected in series to form battery packs with different voltages and energies. Since there are differences between the batteries in series, the batteries with relatively high power among these batteries need to be discharged by passive balancing circuits so that each battery can work in a relatively consistent state as much as possible. However, existing passive balancing circuits generally balance the batteries for a fixed time, which makes the balancing current value of the passive balancing circuit always at a high value. Summary of the invention

[0003] An object of the embodiments of the present disclosure is to provide a new technical solution for battery balancing of a battery pack.

[0004] According to a first aspect of the present disclosure, a battery balancing circuit for a battery pack is provided, the battery pack comprising at least a plurality of batteries, the plurality of batteries being connected in series, characterized in that the battery balancing circuit for the battery pack comprises a control circuit and a plurality of passive balancing circuits, the plurality of passive balancing circuits corresponding to the plurality of batteries one by one, and the two ends of the passive balancing circuit are respectively connected to the positive electrode and the negative electrode of the corresponding battery;

[0005] The control circuit is configured to determine a first balancing current value of the battery in a use state according to a balancing time of the battery in a first setting window and a usage time of the battery in a second setting window when a set parameter value of the battery is greater than a set threshold value; the control circuit is further configured to output a first discharge control signal corresponding to the first balancing current value to a passive balancing circuit corresponding to the battery; wherein the first discharge control signal causes the battery to discharge at the first balancing current value through the corresponding balancing discharge circuit.

[0006] Optionally, the equalization duration is determined according to a difference between the set parameter value and the set threshold value.

[0007] Optionally, the control circuit is further configured to determine the first balancing current value according to a ratio of the balancing time of the battery to the usage time of the battery when the balancing time of the battery is less than or equal to the usage time of the battery; the control circuit is further configured to determine the first balancing current value as a set fixed value when the balancing time of the battery is greater than the usage time of the battery; the control circuit is further configured to output a first discharge control signal corresponding to the first balancing current value to a passive balancing circuit corresponding to the battery when the battery is in use.

[0008] Optionally, when the set parameter value of the battery is greater than a set threshold value, the control circuit is further configured to determine a second balancing current value and an offline balancing time of the battery in a non-use state when the balancing time of the battery is greater than the usage time of the battery; wherein the offline balancing time is determined according to the balancing time of the battery and the usage time of the battery; the control circuit is further configured to output a second discharge control signal corresponding to the second balancing current value to the passive balancing circuit corresponding to the battery within the offline balancing time when the battery is in a non-use state; wherein the second discharge control signal causes the battery to discharge through the corresponding balancing discharge circuit at the second balancing current value.

[0009] Optionally, the second balancing current value is a set fixed value.

[0010] Optionally, the first discharge control signal is a PWM wave corresponding to a first duty cycle, and the second discharge control signal is a PWM wave corresponding to a second duty cycle.

[0011] Optionally, the setting parameter value is a numerical value of a setting parameter, and the setting parameter is voltage and / or power.

[0012] Optionally, the battery balancing circuit for the battery pack further includes a temperature detection circuit, and the temperature detection circuit detects temperature values ​​of the plurality of passive balancing circuits;

[0013] The control circuit is further configured to obtain a detection signal output by the temperature detection circuit regarding a temperature value of a passive balancing circuit corresponding to the battery; the control circuit is further configured to output a control signal to the passive balancing circuit corresponding to the battery when the detection signal indicates that the temperature value of the passive balancing circuit corresponding to the battery exceeds a set temperature value; wherein the control signal causes the balancing discharge circuit corresponding to the battery to reduce or cut off a discharge current.

[0014] Optionally, the control circuit and the passive balancing circuit in the battery balancing circuit for the battery pack are integrated on the same circuit board.

[0015] Optionally, the passive balancing circuit includes at least one load and a switch tube, the control end of the switch tube is the control end of the passive balancing circuit, and the load is connected between the switch tube and the corresponding battery.

[0016] According to a second aspect of the present disclosure, a battery pack is also provided, comprising:

[0017] a plurality of batteries, the plurality of batteries being connected in series;

[0018] A battery balancing circuit for a battery pack, wherein the battery balancing circuit for a battery pack is the battery balancing circuit for a battery pack according to the first aspect, and the battery balancing circuit for a battery pack is used to balance the multiple batteries.

[0019] According to a third aspect of the present disclosure, there is also provided an electric energy device, comprising:

[0020] A battery equalization circuit for a battery pack, wherein the battery equalization circuit for a battery pack is the battery equalization circuit for a battery pack as described in the first aspect;

[0021] or,

[0022] A battery pack, wherein the battery pack is the battery pack as described in the second aspect.

[0023] One beneficial effect of the disclosed embodiment is that, when the set parameter value of the battery is greater than the set threshold, the first balancing current value can be determined according to the balancing time and the use time of the battery within the set window, and the battery is controlled to discharge with the first balancing current value through the passive balancing circuit. In other words, by using the balancing time required by the battery and the use time of the battery reasonably, the battery can be discharged with a lower current value, which reduces the temperature of the balancing discharge circuit, thereby improving the reliability of the battery pack.

[0024] Other features and advantages of the embodiments of the present disclosure will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the embodiments of the present disclosure.

[0026] Figure 1 is a schematic diagram of a composition structure of a battery equalization circuit for a battery pack to which one embodiment can be applied;

[0027] Figure 2 is a circuit diagram of a cell equalization circuit for a battery pack according to one embodiment;

[0028] Figure 3 is a circuit diagram of a cell balancing circuit for a battery pack according to another embodiment. DETAILED DESCRIPTION

[0029] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0030] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0031] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0032] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0033] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0034] Figure 1 FIG. 1 is a schematic diagram of a battery equalization circuit for a battery pack that can be applied according to an embodiment. Figure 1 As shown, the battery pack includes a plurality of batteries 10, and the battery balancing circuit for the battery pack includes a plurality of passive balancing circuits 20 and a control circuit 30. The battery balancing circuit for the battery pack can be applied to the battery pack scenario.

[0035] The above multiple batteries 10 are connected in series, and the capacity, voltage range, and number of batteries 10 connected in series are not limited here.

[0036] The above multiple passive balancing circuits 20 correspond to multiple batteries 10 one by one, and two ends of the passive balancing circuit 20 are respectively connected to the positive electrode and the negative electrode of the corresponding battery 10 to form a balanced discharge circuit, which can consume or transfer the power of the corresponding battery 10.

[0037] The control circuit 30 described above can control one or more of the multiple passive balancing circuits 20 , so that one or more passive balancing circuits 20 can consume or transfer the power of the corresponding battery 10 .

[0038] In some embodiments, the control circuit 30 may include a collector 31 and a control chip 32. The collector 31 is, for example, an analog front end chip (Analog Front End, AFE). The collector 31 has the functions of voltage sampling and balancing control. The collector 31 can collect the voltages of multiple batteries 10 and can also control the passive balancing circuits 20 corresponding to the multiple batteries 10. The control chip 32 is, for example, a baseboard management controller 30 (Baseboard Management Controller, BMC). The control chip 32 can control multiple collectors 31 to perform voltage sampling or balancing control.

[0039] The control circuit 30 is configured to determine a first balancing current value of the battery 10 in use according to the balancing time of the battery 10 in the setting window and the usage time of the battery 10 in the setting window when the setting parameter value of the battery 10 is greater than the setting threshold.

[0040] In some embodiments, the set parameter value is a numerical value of the set parameter, and the set parameter is at least one of voltage or power.

[0041] In this embodiment, when multiple batteries 10 are in different scenarios such as charging, running or not running, the control circuit 30 can collect the voltage V(i) or charge SOC(i) of the i-th battery 10 at the charging end of the i-th battery 10.

[0042] In this embodiment, the set threshold value may be a preset fixed value, or may be a maximum value or a minimum value among the multiple batteries 10 , which is not limited here.

[0043] In some embodiments, the set threshold is the minimum value among the set parameter values ​​of the multiple batteries 10. For example, the power of the battery 10A is 40%, the power of the battery 10B is 44%, and the power of the battery 10C is 42%. The power of 40% corresponding to the battery 10A is the set threshold, and the set parameter values ​​of the batteries 10B and 10C are both greater than the set threshold.

[0044] In this embodiment, the balancing time is the shortest time that the battery 10 needs to be discharged through the passive balancing circuit 20 .

[0045] In this embodiment, the usage time is the average time that the battery 10 is in use during a set period, and the set period can be 6 hours, one day, or one week, which is not limited here. For example, if the set period is 1 day, the control circuit 30 can obtain the average daily time that the battery 10 is in use within the previous 30 days. Among them, the battery 10 in use can be understood as the battery 10 being charged or powered based on the user's operation instructions.

[0046] In this embodiment, the setting window can be a time period, such as one day, one week, or one month. The first setting window and the second setting window can correspond to different time periods, and each time period corresponds to the same day, one week, or one month. The first setting window can correspond to the current period, and the second setting window can correspond to the historical period, and the time of the current period is after the historical period. The historical period can be the period before the current period, can be a period that is multiple time periods away from the current period, or can be several periods before the current period, which is not limited here. Taking the historical period as an example of the period before the current period, the current period is the current day, the historical period is yesterday, and the usage time of yesterday is, for example, 3 hours or 5 hours used yesterday, and the balanced time of the day is, for example, 3 hours or 6 hours that need to be balanced on the day. Taking the historical period as an example of the 3 periods before the current period, the current period is the current day, the historical period is the previous 3 days, and the usage time of the previous 3 days is, for example, 2 hours or 6 hours used on average on the previous 3 days, and the balanced time of the day is, for example, 2 hours or 6 hours that need to be balanced on the day. When the balancing time is longer than the usage time, the control circuit 30 controls the battery 10 to discharge at a first current value of a first fixed value through the passive balancing circuit 20 during the usage time, and the control circuit 30 discharges at a first current value of a second fixed value through the passive balancing circuit 20 during the portion where the balancing time is longer than the usage time, wherein the first fixed value may be the same as or different from the second fixed value, and is not limited here. For example, when the balancing time is 3 hours and the usage time is 2 hours, the first fixed value and the second fixed value may both be current values ​​corresponding to a duty cycle of 100%, so as to balance the battery through a shorter time, thereby achieving the purpose of shortening the offline balancing time. Among them, this part of time is when the battery 10 is in a dormant state, and some components of the control circuit 30 corresponding to the balancing function work. When the balancing time is less than or equal to the usage time, the control circuit 30 may control the battery 10 to discharge at a lower first current value through the passive balancing circuit 20 during the usage time.

[0047] In some embodiments, the equalization duration is determined according to a difference between a set parameter value and a set threshold value.

[0048] In this embodiment, the difference between the set parameter value and the set threshold value can be input into a preset algorithm to obtain the equalization duration, which is manually set and is not limited here. The difference between the set parameter value and the set threshold value can also be used to obtain the equalization duration according to a preset mapping relationship, in which different differences correspond to different equalization durations, which is also manually set and is not limited here.

[0049] In some examples, the setting parameter is power, and the mapping relationship is that the difference is 2% corresponding to a balancing time of 20 hours. The setting parameter value of battery A is 73%, the setting parameter value of battery B is 72%, and the setting parameter value of battery C is 71%. The setting threshold is 70%, the difference corresponding to battery A is 3%, and the balancing time is 30 hours, the difference corresponding to battery B is 2%, and the balancing time is 20 hours, and the difference corresponding to battery C is 1%, and the balancing time is 10 hours.

[0050] In other words, by determining the balancing time by the difference between the set parameter value and the set threshold value, a reference can be provided for the subsequent battery 10 to consume different differences with smaller current values.

[0051] The control circuit 30 is further configured to output a first discharge control signal corresponding to the first balancing current value to the passive balancing circuit 20 corresponding to the battery 10; wherein the first discharge control signal enables the battery 10 to discharge at the first balancing current value through the corresponding balancing discharge circuit.

[0052] In this embodiment, the first discharge control signal is a signal that can enable a balanced discharge circuit to pass. The first discharge control signal may be a level signal or a pulse signal, such as a PWM wave, which is not limited here.

[0053] In other words, when the set parameter value of the battery 10 is greater than the set threshold, the first balancing current value can be determined according to the balancing time and the use time of the battery 10 within the set window, and the battery 10 can be controlled to discharge at the first balancing current value through the passive balancing circuit 20. In other words, by using the balancing time required by the battery 10 and the use time of the battery 10 reasonably, the battery 10 can be discharged at a lower current value, thereby reducing the temperature of the balancing discharge circuit and improving the reliability of the battery pack.

[0054] In some embodiments, in order to enable the battery 10 to discharge at a lower current value during use, the control circuit 30 is further configured to determine the first balancing current value according to the ratio of the balancing time of the battery 10 to the usage time of the battery 10 when the balancing time of the battery 10 is less than or equal to the usage time of the battery 10.

[0055] In some examples, different values ​​of the balancing current value may correspond to different values ​​of the duty cycle, and the specific corresponding relationship is not limited here.

[0056] For example, the first balancing current value is represented by a duty cycle, the balancing time is 2 hours, the use time is 2 hours, and the time ratio is 1:1. Then, the duty cycle corresponding to the first balancing current value is 100%.

[0057] For another example, the first balancing current value is represented by a duty cycle, the balancing time is 2 hours, the use time is 4 hours, and the time ratio is 1:2. Then, the duty cycle corresponding to the first balancing current value is 50%.

[0058] For another example, the first balancing current value is represented by a duty cycle, the balancing time is 2 hours, the use time is 8 hours, and the time ratio is 1:4. Then, the duty cycle corresponding to the first balancing current value is 25%.

[0059] The control circuit 30 is further configured to determine the first balancing current value to be a set fixed value when the balancing time of the battery 10 is greater than the service time of the battery 10 .

[0060] For example, the first balancing current value is expressed in terms of duty cycle, the balancing time is 2 hours, and the use time is 1 hour, then the fixed value corresponding to the first balancing current value is the duty cycle of 100%, and the battery 10 is discharged at the first balancing current value corresponding to the duty cycle of 100% through the passive balancing circuit 20 during the use time of 1 hour. Moreover, during the 1 hour when the battery 10 is in the dormant state, some components of the control circuit 30 corresponding to the balancing function work, and the battery 10 is discharged at the first balancing current value corresponding to the duty cycle of 100% through the passive balancing circuit 20 during this 1 hour.

[0061] The control circuit 30 is further configured to output a first discharge control signal corresponding to a first balancing current value to the passive balancing circuit 20 corresponding to the battery 10 when the battery 10 is in use.

[0062] In other words, through the relationship between the balancing time and the usage time, different first balancing current values ​​can be set, so that under the premise of ensuring the balancing time in the set window is completed, the battery 10 is discharged with a smaller first balancing current value during a longer usage time, thereby reducing the temperature of the passive balancing circuit 20 and improving the reliability of the battery pack.

[0063] In some embodiments, in order to ensure that the battery 10 can complete the balancing time of each set window, the control circuit 30 is also configured to determine the second balancing current value and the offline balancing time of the battery 10 in a non-use state when the balancing time of the battery 10 is greater than the usage time of the battery 10; wherein the offline balancing time is determined based on the balancing time of the battery 10 and the usage time of the battery 10.

[0064] In this embodiment, the non-use state of the battery 10 may be that the battery 10 is in a dormant state, that is, the battery 10 is not charged or is not supplying power.

[0065] In this embodiment, the offline balancing time is the time that the battery 10 needs to be discharged when the battery 10 is in a dormant state.

[0066] In this embodiment, the offline balancing time may be the balancing time of the battery 10 minus the usage time of the battery 10 . For example, if the balancing time is 2 hours and the usage time is 1 hour, then the offline balancing time is 1 hour.

[0067] In some embodiments, in order to shorten the offline balancing time to shorten the working time of the control circuit 30, the second balancing current value can be a set fixed value. For example, the balancing time is 2 hours, the use time is 1 hour, and the duty cycle corresponding to the first balancing current value is 100%. Then, the offline balancing time is 1 hour, and the fixed value corresponding to the second balancing current value is a duty cycle of 100%. This allows the battery 10 to discharge with a shorter offline balancing time when the battery 10 is not in use, thereby shortening the working time of the control circuit 30.

[0068] The control circuit 30 is further configured to output a second discharge control signal corresponding to a second balancing current value to the passive balancing circuit 20 corresponding to the battery 10 during an offline balancing time when the battery 10 is not in use; wherein the second discharge control signal enables the battery 10 to discharge through the corresponding balancing discharge circuit at the second balancing current value.

[0069] In this embodiment, the second discharge control signal is a signal that can enable a balanced discharge circuit to pass. The second discharge control signal may be a level signal or a pulse signal, such as a PWM wave, which is not limited here.

[0070] For example, the second discharge control signal is a PWM wave, the offline balancing time is 1 hour, and the duty cycle corresponding to the second balancing current value is 100%. Then, the battery 10 can be discharged for 1 hour through the passive balancing circuit 20 at the second balancing current value corresponding to the duty cycle of 100%.

[0071] In some embodiments, in order to improve the control accuracy of the first balancing current value and the second balancing current value, the first balancing current value is represented by a first duty cycle, and the second balancing current value is represented by a second duty cycle. The first duty cycle and the second duty cycle reflect the on-off ratio of the balancing discharge circuit corresponding to the battery 10 within the control period; the first discharge control signal is a PWM wave corresponding to the first duty cycle, and the second discharge control signal is a PWM wave corresponding to the second duty cycle.

[0072] For example, the first balancing current value of battery A corresponds to a duty cycle of 50%, and the first balancing current value of battery B corresponds to a duty cycle of 75%. Battery A and battery B both correspond to passive balancing circuits 20 with the same resistance load. Accordingly, when the two passive balancing circuits 20 are both working, the temperature value of the passive balancing circuit 20 corresponding to battery A will be lower than the temperature value of the passive balancing circuit 20 corresponding to battery B.

[0073] In some embodiments, in order to reduce the impact of excessive temperature of the passive balancing circuit 20 on the service life of the battery pack, the battery balancing circuit for the battery pack further includes a temperature detection circuit 40, which is connected to the control circuit 30 to output the detected temperature values ​​of the multiple passive balancing circuits 20 to the control circuit 30.

[0074] by Figure 2 For example, the temperature detection circuit 40 may include a thermistor R5 and a reference resistor R6 connected in series, the other end of the thermistor R5 is grounded, the other end of the reference resistor R6 is connected to the end of the collector 31, and the connection point of the thermistor R5 and the reference resistor R6 is connected to the end of the collector 31. The end of the collector 31 can discharge to the reference resistor R6, and the passive balancing circuit 20 generates heat in the process of consuming or transferring the power of the corresponding battery 10, so that the resistance value of the thermistor R5 changes after being heated, so that the current value at the connection point of the thermistor R5 and the reference resistor R6 detected by the end of the collector 31 changes, thereby detecting the temperature value transmission change of multiple passive balancing circuits 20.

[0075] The control circuit 30 is further configured to obtain a detection signal outputted by the temperature detection circuit 40 regarding a temperature value of the passive balancing circuit 20 corresponding to the battery 10 .

[0076] After outputting the first discharge control signal, the control circuit 30 may control the temperature detection circuit 40 to feed back a detection signal to obtain a temperature value of the passive balancing circuit 20 corresponding to the battery 10 being balanced.

[0077] The control circuit 30 is further configured to output a control signal to the passive balancing circuit 20 corresponding to the battery 10 when the detection signal indicates that the temperature value of the passive balancing circuit 20 corresponding to the battery 10 exceeds the set temperature value; wherein the control signal causes the balancing discharge circuit corresponding to the battery 10 to reduce or cut off the discharge current.

[0078] In this embodiment, the set temperature value is, for example, 50° C., 60° C. or 80° C., which is not limited here.

[0079] When the temperature value indicated by the acquired detection signal exceeds the set temperature value, the control circuit 30 may output a control signal to the passive balancing circuit 20 corresponding to the battery 10, and the control signal may reduce the discharge current of the balancing discharge circuit corresponding to the battery 10 to a specific value, which may be any value set manually, or cut off the discharge current of the balancing discharge circuit corresponding to the battery 10, which is not limited here.

[0080] In some embodiments, each circuit in the battery balancing circuit for a battery pack is integrated on the same circuit board. Figure 1 As shown, the control circuit 30 and the passive balancing circuit 20 are integrated on the same circuit board. For another example, the control circuit 30, the passive balancing circuit 20 and the temperature detection circuit 40 are integrated on the same circuit board. For another example, Figure 2 As shown, the collector 31, the passive balancing circuit 20 and the temperature detection circuit 40 in the control circuit 30 are integrated on the same circuit board. In other words, integrating all or part of the circuits in the battery balancing circuit on a circuit board can effectively improve the overall integration of the battery balancing circuit for the battery pack.

[0081] In some embodiments, the passive balancing circuit 20 includes at least one load and a switch tube. The control end of the switch tube is the control end of the passive balancing circuit 20 , and the load is connected between the switch tube and the corresponding battery 10 .

[0082] by Figure 2 For example, for the first battery Bat1, the load is two and is respectively a first resistor R1 and a second resistor R2, the switch tube is a MOS tube Q1, the first resistor R1 is connected between the positive electrode of the first battery Bat1 and the drain of the MOS tube Q1, the second resistor R2 is connected between the negative electrode of the first battery Bat1 and the source of the MOS tube Q1, and the collector 31 in the control circuit 30 can output a PWM wave to control the conduction or disconnection of the MOS tube Q1. When the MOS tube Q1 is turned on, the first battery Bat1 can be discharged through the first resistor R1 and the second resistor R2.

[0083] For the second battery Bat2, the load is two and they are the third resistor R3 and the fourth resistor R4, the switch tube is the MOS tube Q2, the third resistor R3 is connected between the positive electrode of the second battery Bat2 and the drain of the MOS tube Q2, the fourth resistor R4 is connected between the negative electrode of the second battery Bat2 and the source of the MOS tube Q2, and the collector 31 in the control circuit 30 can output a PWM wave to control the conduction or disconnection of the MOS tube Q2. When the MOS tube Q2 is turned on, the second battery Bat2 can be discharged through the third resistor R3 and the fourth resistor R4.

[0084] In some examples, the switch in the passive balancing circuit 20 may be a part of the collector 31, for example, Figure 2 As shown, the MOS transistor Q1 and the MOS transistor Q2 are both part of the collector 31, or may be independent parts electrically connected to the collector 31, for example, Figure 3 As shown, the MOS transistor Q1 and the MOS transistor 2 are electrically connected to the collector 31 respectively.

[0085] In some embodiments, the battery pack further includes a temperature detection circuit 40 , which is connected to the control circuit 30 to output the detected temperature values ​​of the plurality of passive balancing circuits 20 to the control circuit 30 .

[0086] According to the battery pack provided by the embodiment of the present disclosure, the battery pack includes a plurality of batteries 10 and a battery balancing circuit for a battery pack, the plurality of batteries 10 are connected in series, the battery balancing circuit for the battery pack is the battery balancing circuit for the battery pack of any of the above embodiments, and the battery balancing circuit for the battery pack is used to balance the plurality of batteries 10. In other words, the battery pack can maintain a relatively low temperature during the battery 10 balancing process to extend the service life of the battery pack.

[0087] According to the electric energy device provided by the embodiment of the present disclosure, the electric energy device includes the battery balancing circuit for a battery pack of any of the above embodiments or the battery pack of any of the above embodiments. The electric energy device can be a ship, a vehicle, an aircraft, a charging point or an energy storage cabinet, etc., which is not limited here. In other words, the electric energy device can maintain a lower temperature during the battery 10 balancing process to extend the service life of the electric energy device.

[0088] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A battery equalization circuit for a battery pack, the battery pack comprising at least a plurality of batteries, the plurality of batteries being connected in series, characterized in that: The battery balancing circuit for the battery pack includes a control circuit and a plurality of passive balancing circuits, the plurality of passive balancing circuits correspond to the plurality of batteries one by one, and two ends of the passive balancing circuit are respectively connected to the positive electrode and the negative electrode of the corresponding battery; The control circuit is configured to determine a first balancing current value of the battery in a use state according to a balancing time of the battery in a first setting window and a usage time of the battery in a second setting window when a set parameter value of the battery is greater than a set threshold value; the control circuit is further configured to output a first discharge control signal corresponding to the first balancing current value to a passive balancing circuit corresponding to the battery; wherein the first discharge control signal causes the battery to discharge at the first balancing current value through the corresponding balancing discharge circuit.

2. The battery equalization circuit for a battery pack according to claim 1, characterized in that: The equalization duration is determined according to the difference between the set parameter value and the set threshold value.

3. The battery equalization circuit for a battery pack according to claim 1, characterized in that: The control circuit is further configured to determine the first balancing current value according to a ratio of the balancing time of the battery to the usage time of the battery when the balancing time of the battery is less than or equal to the usage time of the battery; the control circuit is further configured to determine the first balancing current value as a set fixed value when the balancing time of the battery is greater than the usage time of the battery; the control circuit is further configured to output a first discharge control signal corresponding to the first balancing current value to a passive balancing circuit corresponding to the battery when the battery is in use.

4. The battery equalization circuit for a battery pack according to claim 3, characterized in that: When the set parameter value of the battery is greater than a set threshold value, the control circuit is further configured to determine a second balancing current value and an offline balancing time of the battery in a non-use state when the balancing time of the battery is greater than the usage time of the battery; wherein the offline balancing time is determined according to the balancing time of the battery and the usage time of the battery; the control circuit is further configured to output a second discharge control signal corresponding to the second balancing current value to the passive balancing circuit corresponding to the battery within the offline balancing time when the battery is in a non-use state; wherein the second discharge control signal causes the battery to discharge through the corresponding passive balancing circuit at the second balancing current value.

5. The battery equalization circuit for a battery pack according to claim 4, characterized in that: The second balancing current value is a set fixed value.

6. The battery equalization circuit for a battery pack according to claim 4, characterized in that: The first discharge control signal is a PWM wave corresponding to a first duty cycle, and the second discharge control signal is a PWM wave corresponding to a second duty cycle.

7. The battery equalization circuit for a battery pack according to claim 1, characterized in that: The setting parameter value is a numerical value of a setting parameter, and the setting parameter is voltage and / or power.

8. The battery equalization circuit for a battery pack according to claim 1, characterized in that: The battery balancing circuit for a battery pack further comprises a temperature detection circuit, wherein the temperature detection circuit detects temperature values ​​of the plurality of passive balancing circuits; The control circuit is further configured to obtain a detection signal output by the temperature detection circuit regarding a temperature value of a passive balancing circuit corresponding to the battery; the control circuit is further configured to output a control signal to the passive balancing circuit corresponding to the battery when the detection signal indicates that the temperature value of the passive balancing circuit corresponding to the battery exceeds a set temperature value; wherein the control signal causes the balancing discharge circuit corresponding to the battery to reduce or cut off a discharge current.

9. The battery equalization circuit for a battery pack according to claim 1 or 8, characterized in that: The control circuit and the passive equalization circuit in the battery equalization circuit are integrated on the same circuit board.

10. The battery balancing circuit for a battery pack according to claim 1, wherein the passive balancing circuit comprises at least one load and a switch tube, the control end of the switch tube is the control end of the passive balancing circuit, and the load is connected between the switch tube and the corresponding battery.

11. A battery pack, characterized in that: include: a plurality of batteries, the plurality of batteries being connected in series; A battery balancing circuit for a battery pack, wherein the battery balancing circuit for a battery pack is the battery balancing circuit for a battery pack according to any one of claims 1 to 9, and the battery balancing circuit for a battery pack is used to balance the multiple batteries.

12. An electric energy device, characterized in that: include: A battery equalization circuit for a battery pack, wherein the battery equalization circuit for a battery pack is the battery equalization circuit for a battery pack according to any one of claims 1 to 10; or, A battery pack, wherein the battery pack is the battery pack according to claim 11.

Images