TWI568131B - System and method for battery charging - Google Patents

Description

Battery system and battery charging method

The present invention relates to the field of batteries, and more particularly to a battery system and a battery charging method.

A battery system includes a plurality of battery cells (eg, lithium ion batteries), which are typically powered by a cell phone, laptop, or electric vehicle. Battery equalizers are widely used in battery systems to maximize battery unit capacity and increase battery life. If the battery cells in the battery system are unbalanced, the battery equalizer equalizes the battery cells by transferring energy on the battery cells with the highest charge or by transferring the energy on the battery cells with the highest charge to the battery cells with the lowest charge. .

FIG. 1 is a waveform diagram 100 of a charging current and a cell voltage in a charging process of a lithium ion battery in the prior art. The charging process of a lithium ion battery has undergone multiple modes (for example, a constant current charging mode and a constant voltage charging mode). At time t0, the battery unit has a voltage value of V10 and is charged by a charging current. During the time period t0-t3, the battery unit operates in a constant current charging mode during which the charging current is constant and the cell voltage is increased from V10 to VM. During the period t3-t4, the battery unit enters a constant voltage charging mode during which the charging current is gradually decreased and the battery cell voltage is kept constant. For example, the cell voltage remains as VM during time period t3-t4. At time t4, the charging current drops below a current threshold. Accordingly, the battery charging process ends.

The cell voltage has a relatively low rate of growth during a period of constant current charging mode (this period is referred to as the plateau voltage region). For example, during time period t1-t2, the rate of increase of the cell voltage is below a rate threshold. Since the charging current is constant, the rate of increase of the cell power should be kept constant for any period of the constant current charging mode. Therefore, in the platform voltage region, the cell voltage has a low growth rate and cannot accurately reflect the change in the cell power.

Thus, for a battery pack that contains multiple battery cells, the battery equalizer may perform equalization operations when all of the battery cells are in the platform voltage region. Since the battery cell voltage cannot accurately reflect the battery cell power, it is difficult for the battery equalizer to accurately detect the imbalance by monitoring the battery cell voltage of the battery unit. For example, by equalization, although the amount of the battery with the highest charge drops to the same amount as the battery with the lowest charge, the voltage of the battery does not change with the change of the amount of the battery. Therefore, the equalization control of the battery equalizer may not be accurate.

An object of the present invention is to provide a battery system comprising: a plurality of battery cells having a plurality of battery cell voltages; and an equalization module coupled to the plurality of battery cells, according to the plurality of battery cells in a constant current charging mode a lower charging current is set to a first voltage threshold, and when one of the plurality of battery cell voltages does not meet the requirement of the first voltage threshold, starting one of the plurality of battery cells Balance check.

The invention also provides a battery charging method, comprising: charging a plurality of battery cells by a charging current, the plurality of battery cells having a plurality of battery cell voltages; setting a first according to the charging current in a constant current charging mode a voltage threshold; and when a battery cell voltage of the plurality of battery cell voltages does not satisfy the first voltage threshold, an equalization check of the plurality of battery cells is initiated.

The present invention also provides a battery system comprising: a plurality of battery modules connected in series, wherein each of the battery modules includes a plurality of battery cells, the plurality of battery cells having a plurality of battery cell voltages; and a plurality of equalization modules The plurality of battery modules are coupled to each of the plurality of battery modules, wherein each of the equalization modules sets a first voltage threshold according to a charging current of the plurality of battery cells in a constant current charging mode, and when the plurality of batteries When a cell voltage in the cell voltage does not satisfy the requirement of the first voltage threshold, an equalization check of the plurality of cells is initiated.

100‧‧‧ Waveform

200‧‧‧ schematic diagram of a battery system according to an embodiment of the present invention

205‧‧‧Charger

210‧‧‧Equilibrium Module

290‧‧‧Charging pathway

300‧‧‧ Waveform

301, 302‧‧‧Charging curve

400‧‧‧System block diagram of a battery system according to an embodiment of the present invention

401‧‧‧Equilibrium circuit

402‧‧‧Monitoring circuit

403‧‧‧ Analog Digital Converter

404‧‧‧ processor

411‧‧‧resistance

421~423, 460‧‧‧ monitoring signals

440‧‧‧ digital signal

470‧‧‧Control instructions

480‧‧‧balanced signal

500‧‧‧System block diagram of a battery system according to another embodiment of the present invention

504‧‧‧ processor

510‧‧‧Equilibrium Module

531~533‧‧‧Comparative signal

540‧‧‧ digital signal

541~543‧‧‧ comparator

600‧‧‧Block diagram of a battery system according to still another embodiment of the present invention

601, 602‧‧‧ battery module

609‧‧‧Battery Pack

611, 612‧‧‧Equilibrium Module

700‧‧‧Flowchart

701~705‧‧‧Steps

The technical method of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments to make the features and advantages of the present invention more obvious. Wherein: FIG. 1 is a waveform diagram of charging current and battery cell voltage in a charging process of a lithium ion battery in the prior art; 2 is a block diagram of a battery system according to an embodiment of the invention; FIG. 3 is a waveform diagram of battery cell voltages during a charging phase of a battery unit according to an embodiment of the invention; FIG. 5 is a block diagram of a system of a battery system according to another embodiment of the present invention; FIG. 6 is a block diagram of a battery system according to still another embodiment of the present invention; FIG. 7 is a flow chart showing an equalization method of a battery system according to an embodiment of the invention.

A detailed description of the embodiments of the present invention will be given below. While the invention will be described in conjunction with the embodiments, it is understood that the invention is not limited to the embodiments. Rather, the invention is to cover various modifications, equivalents, and equivalents of the invention as defined by the scope of the appended claims.

In addition, in the following detailed description of the embodiments of the invention However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail in order to facilitate the invention.

2 is a block diagram 200 of a battery system in accordance with an embodiment of the present invention. In the embodiment shown in FIG. 2, the battery system includes a battery unit C1, a battery unit C2, and a battery unit C3, and an equalization module 210. Although the embodiment shown in FIG. 2 shows three battery cells, the invention is not limited thereto, and the battery system 200 may include other numbers of battery cells. In an embodiment of the invention, the battery cells C1 to C3 may be lithium ion batteries. The battery unit C1 to the battery unit C3 are coupled to the equalization module 210. The equalization module 210 monitors battery unit parameters (for example, battery unit voltage, battery unit current, battery unit temperature, battery unit power, etc.) of each of the battery cells C1 to C3, and determines the battery unit C1 to the battery unit. Whether C3 has an imbalance. When an imbalance condition is detected, the equalization module 210 equalizes the battery cells C1 to C3.

In one embodiment of the invention, the battery cells C1 to C3 are coupled to the charger 205 through the charging path 290. The charging path 290 includes a switch S5. When the switch S5 is turned on, the battery cells C1 to C3 operate in a charging mode (for example, a constant current charging mode or a constant voltage charging mode). At this time, the charger 205 uses the charging current I _CHARGE as the battery unit C1 to the battery unit. C3 charging. When the switch S5 is turned off or the charger 205 is not coupled to the battery unit C1 to the battery unit C3, the battery unit C1 to the battery unit C3 are in the rest mode or the discharging mode, and the charging process ends.

3 is a waveform diagram 300 of a cell voltage VCELL of a battery cell during a charging phase, in accordance with an embodiment of the present invention. Figure 3 will be described in conjunction with Figure 2.

In the embodiment shown in FIG. 3, waveform diagram 300 includes a charging curve 301 and a charging curve 302. The charging curve 301 represents a change in the cell voltage V _CELL when the battery cell is charged by the charging current I _CHARGE1 . Charging curve 302 represents the change in cell voltage V _CELL when the battery cell is charged by charging current I _CHARGE2 . In one embodiment of the invention, the charging current I _{CHARGE1 is} greater than the charging current I _CHARGE2 . Although FIG. 3 shows two charging curves, the present invention is not limited thereto, and FIG. 3 may also include charging curves corresponding to other charging currents. In one embodiment of the invention, these charging profiles are provided by the battery manufacturer.

More specifically, in one embodiment of the present invention, as shown in the charging curve 301, when the battery unit is charged by the charging current I _CHARGE1 , the battery unit operates in the constant current charging mode during the period t0~t5, after the time t5. , working in constant voltage charging mode. In the constant current charging mode, the charging current I _CHARGE1 remains constant and the cell voltage V _CELL increases. In the constant voltage charging mode, the cell voltage V _{CELL is} maintained at V _M and the charging current I _{CHARGE1 is} decreased. In the embodiment shown in FIG. 3, the charging curve 301 is in the platform voltage region T _FLAT1 during the period t1 to t2, during which the cell cell voltage V _CELL is grown at a rate below a rate threshold. Similarly, as shown in the charging curve 302, when the battery unit is charged by the charging current I _CHARGE2 , the battery unit operates in the constant current charging mode during the period t0~t6, and after the time t6, the battery unit operates in the constant voltage charging mode. under. Similar to the charging curve 301, the charging curve 302 is in the platform voltage region T _{FLAT2 for the} period t3~t4.

2 and FIG. 3, the equalization module 210 detects whether the battery cells C1 to C3 are unbalanced, and equalizes the battery cells C1 to C3 when the imbalance is detected. Advantageously, the equalization module 210 initiates an equalization operation when at least one of the battery cells is operating outside of the platform voltage region. More specifically, in one embodiment of the present invention, the equalization module 210 provides a voltage threshold V _H, V _H is higher than the threshold voltage of the battery cell voltage unit operates the maximum value of the plateau voltage region. For example, according to the charging curve 301, when the battery unit is charged by the charging current I _CHARGE1 , the voltage threshold V _{H1 is} greater than the battery cell voltage at time t2.

If one or more battery cell voltages in the cell voltage V _C1 ~ cell voltage V _C3 are higher than the voltage threshold V _H , it indicates that one or more of the battery cells C1 C C3 are operating at the platform voltage. Outside the area, when an imbalance is detected, the equalization module 210 starts detecting the cell voltage V _C1 ~ cell voltage V _C3 and equalizing the cell C1 ~ C3. For example, the equalization module 210 compares the maximum cell voltage V _MAX and the minimum cell voltage V _{MIN in the} battery cells C1 to C3. When the difference between the maximum cell voltage V _MAX and the minimum cell voltage V _MIN is greater than a threshold V _DIF , an imbalance occurs. The equalization module 210 equalizes the battery cells C1 to C3. For example, the equalization module 210 identifies the battery cells C _MAX having the largest battery cell voltage V _MAX and equalizes the battery cells C1 to C3 by consuming the power of the battery cells C _MAX . In another embodiment of the present invention, the equalization module 210 further identifies the battery unit C _MIN having the smallest battery cell voltage V _MIN and equalizes the battery unit C1 by transferring the amount of power in the battery unit C _MAX to the battery unit C _MIN . ~ Battery unit C3. The equalization module 210 can also perform other operations to detect imbalances and equalize the battery cells C1 through C3 without being limited to the embodiment of FIG.

Advantageously, the equalization module 210 adjusts the voltage threshold V _H based on the charging current I _CHARGE . The voltage threshold V _{H is} greater than the maximum cell voltage at which the cell operates in the platform voltage region. As shown in FIG. 3, the cell voltage in the platform voltage region T _FLAT1 of the charging curve 301 is higher than the cell voltage in the plate voltage region T _FLAT2 of the charging curve 302. Therefore, when the battery unit is charged by the charging current I _CHARGE1 , the equalization module 210 sets the voltage threshold V _H to V _H1 , and when the battery unit is charged by the charging current I _CHARGE2 , the equalization module 210 sets the voltage threshold V _{H is} set to V _H2 . In other words, the voltage threshold value V _{H changes in} accordance with the charging current flowing through the battery cells C1 to C3. Therefore, even if the stage voltage region changes due to the charging current, the equalization operation is not performed until at least one of the battery cells operates outside the platform voltage region. In this way, battery equalization control will be more accurate.

In yet another embodiment of the invention, the equalization module 210 provides a voltage threshold V _L, V _L voltage threshold below the minimum cell voltage of the cell voltage of the working platform area. The voltage threshold V _{L is} adjusted according to the charging current I _CHARGE . As shown in the charging curve 301 of FIG. 3, when the charging current is I _CHARGE1 , the voltage threshold V _{L is} lower than the cell voltage of the battery cell at time t1. When the charging current is I _CHARGE1 , the voltage threshold V _{L is} set to V _L1 , and when the charging current is I _CHARGE2 , the voltage threshold V _{L is} set to V _L2 . In this case, when the battery cell voltage of the cell C1 ~ C3 cell of at least one battery cell is lower than the threshold voltage V _L, equalization module 210 perform equalization operations.

In another embodiment of the invention, the equalization module 210 provides a voltage threshold V _H and a voltage threshold V _L . For example, when the battery unit is charged by the charging current I _CHARGE1 , the voltage threshold V _{H is} set to V _H1 and the voltage threshold V _{L is} set to V _L1 . When the battery unit is charged by the charging current I _CHARGE2 , the voltage threshold V _{H is} set to V _H2 and the voltage threshold V _{L is} set to V _L2 . At this time, when at least one of the cell voltage V _C1 to the cell voltage V _C3 is greater than the voltage threshold V _H and/or less than the voltage threshold V _L , the equalization module 210 performs an equalization operation.

Advantageously, in the above three cases, battery equalization is only performed when one or more of the battery cells are operating outside of the platform voltage region. Therefore, battery equalization control will be more accurate.

4 is a block diagram 400 of a system of a battery system in accordance with an embodiment of the present invention. The components labeled the same as in Fig. 2 in Fig. 4 have similar functions. Figure 4 will be described in conjunction with Figures 2 and 3.

In one embodiment of the invention, the equalization module 210 includes a resistor 411, an equalization circuit 401, a monitoring circuit 402, an analog/digital converter 403, and a processor 404. In one embodiment of the invention, the monitoring circuit 402 monitors battery cell parameters (eg, cell voltage and cell current) of each of the battery cells C1 through C3 and generates a plurality of corresponding monitoring signals. In one embodiment of the present invention, the monitoring circuit 402 generates a monitoring signal 421, a monitoring signal 422, and a monitoring signal 423 through the resistor 411. The monitoring signal 421 to the monitoring signal 423 respectively indicate the battery cell voltage VC1~Battery of the battery cell C1~C3. Cell voltage VC3. In one embodiment of the invention, the monitoring circuit 402 monitors the charging current I _CHARGE flowing through the battery cells C1 - C3 and generates a monitoring signal 460 indicative of the charging current I _CHARGE . In another embodiment of the invention, the monitoring circuit 402 also monitors the temperature and charge of the battery cells C1 through C3 and generates corresponding monitoring signals (not shown in FIG. 4).

The analog/digital converter 403 coupled to the monitoring circuit 402 converts the monitor signal 421 - the monitor signal 423 and the monitor signal 460 into a digital signal 440. The processor 404 coupled to the analog/digital converter 403 receives the digital signal 440 to obtain status information of the battery cells C1 to C3.

Processor 404 executes machine executable instructions in accordance with digital signal 440 to control battery cells C1 through C3. More specifically, in one embodiment of the present invention, the processor 404 determines whether an undesired state (eg, an overvoltage condition, an overcurrent condition, an undervoltage condition, etc.) has occurred according to the status information of the battery unit C1 to the battery unit C3. If an undesired state has occurred, the processor 404 controls the monitoring circuit 402 via the control command 470 to protect the battery cells C1 through C3.

In addition, the processor 404 detects the charging current I _CHARGE and sets the voltage threshold V _H and the voltage threshold V _L according to the detected charging current I _CHARGE .

More specifically, in one embodiment of the invention, processor 404 reads a plurality of data sets, each data set indicating a voltage threshold corresponding to the charging current. For example, the charging current I _CHARGE1 , the voltage threshold V _H1 , and/or the voltage threshold V _{L1 are} stored as the first data set; the charging current I _CHARGE2 , the voltage threshold V _H2 , and/or the voltage threshold V _{L2 is} stored as a second data set. The processor 404 detects the charging current I _CHARGE , selects a data set from the plurality of data sets according to the charging current I _CHARGE , and sets the voltage threshold V _H and/or the voltage threshold V _L according to the selected data set. For example, when the charging current I _CHARGE is equal to I _CHARGE1 , the first data set is selected, so the voltage threshold V _{H is} set to V _H1 , and/or the voltage threshold V _{L is} set to V _L1 . Similarly, when the charging current I _CHARGE is equal to I _CHARGE2 , the second data set is selected, so the voltage threshold V _{H is} set to V _H2 , and/or the voltage threshold V _{L is} set to V _L2 . In another embodiment of the invention, each data set indicates a change in battery cell voltage when a battery unit is charged by a corresponding charging current. Each data set represents a charging curve corresponding to the corresponding charging current. For example, the charging curve 301 corresponds to the charging current I _CHARGE1 , and the charging curve 302 corresponds to the charging current I _CHARGE2 . The processor 404 detects the charging current I _CHARGE and selects a data set from a plurality of data sets according to the magnitude of the charging current I _CHARGE . For example, when the charging current I _CHARGE is equal to I _CHARGE1 , the data set corresponding to the charging curve 301 is selected, and when the charging current I _CHARGE is equal to I _CHARGE2 , the data set corresponding to the charging curve 302 is selected. Then, the processor 404 determines a platform voltage region corresponding to the charging curve of the selected data set, and the cell voltage growth rate of the platform voltage region is lower than a rate threshold. Processor 404 sets voltage threshold V _H and/or voltage threshold V _L according to the platform voltage region. Specifically, the processor 404 sets the voltage threshold V _H such that the voltage threshold V _{H is} greater than the maximum cell voltage when the cell operates in the platform voltage region, and/or sets the voltage threshold V _L to cause the voltage The threshold V _{L is} less than the minimum cell voltage at which the cell operates in the platform voltage region. For example, in the charging curve 301, the voltage threshold V _{H is} set to V _H1 , and the voltage threshold V _{L is} set to V _L1 . Similarly, in the charging curve 302, the voltage threshold V _{H is} set to V _H2 and the voltage threshold V _{L is} set to V _L2 .

The voltage threshold V _H and the voltage threshold V _{L are} used to determine if a battery unit is operating outside of the platform voltage region. The processor 404 compares each of the battery cell voltage V _C1 ~ the cell voltage V _C3 with a voltage threshold V _H and/or a voltage threshold V _L . In an embodiment of the invention, if the battery cell voltage of the at least one battery cell is greater than the voltage threshold V _H , the processor 404 determines that at least one of the battery cells operates outside the platform voltage region and begins to detect whether an imbalance has occurred. Happening. For example, when the difference between the maximum battery cell voltage V _MAX and the minimum battery cell voltage V _MIN is greater than the threshold value V _DIF , the battery cells C1 to C3 have an imbalance condition, so the processor 404 starts the equalization operation to equalize. Battery unit C1 ~ battery unit C3. In yet another embodiment of the invention, when the cell voltage of at least one battery cell is less than the threshold voltage V _L, the processor 404 starts to detect whether an imbalance occurs. In another embodiment of the invention, if the battery cell voltage of the at least one battery cell is greater than the voltage threshold V _H or less than the voltage threshold V _L , the processor 404 begins to detect if an imbalance condition has occurred.

In one embodiment of the invention, processor 404 generates equalization signal 480 to equalize battery cells C1 through C3. The monitoring circuit 402 controls the equalization circuit 401 based on the equalization signal 480. More specifically, the monitoring circuit 402 controls the switch S1, the switch S2, and the switch S3 according to the equalization signal 480 to enable bypass current flowing through the battery cell C _MAX and the equalization circuit 401 having the largest cell voltage V _MAX , thus The energy on the battery unit C _MAX is consumed, and the power of the battery unit C _MAX is also reduced. When the battery cells C1 to C3 are in an equalized state, for example, when the difference between the maximum cell voltage V _MAX and the minimum cell voltage V _MIN is lower than the threshold value V _DIF , the equalization operation of the battery cells ends.

FIG. 5 is a block diagram 500 of a system of a battery system in accordance with another embodiment of the present invention. The components labeled the same as in Figures 2 and 4 have similar functions. Figure 5 will be described in conjunction with Figures 2, 3 and 4. The equalization operation performed by the battery system is different from the equalization operation of the battery system 400 of FIG.

In the embodiment shown in FIG. 5, the battery system includes a charger 205 and an equalization module 510. The equalization module 510 includes a resistor 411, an equalization circuit 401, a monitoring circuit 402, an analog/digital converter 403, and a processor 504. The equalization module 510 further includes a comparator 541, a comparator 542 and a comparator 543. The comparator 541 to the comparator 543 are respectively configured to receive the monitoring signal 421, the monitoring signal 422, and the monitoring signal 423, wherein the monitoring signal 421~the monitoring signal 423 The battery cell voltage V _C1 to the cell voltage V _{C3 of the} battery cells C1 to C3 are respectively instructed. The comparator 541 to the comparator 543 compare the monitor signal 421, the monitor signal 422, and the monitor signal 423 with the voltage threshold V _{TH ,} respectively, and generate a comparison signal 531, a comparison signal 532, and a comparison signal 533. The analog/digital converter 403 converts the comparison signal 531 to the comparison signal 533 into a digital signal 540 and transmits the digital signal 540 to the processor 504.

Processor 504 executes machine executable instructions in accordance with digital signal 540 to control battery cells C1 through C3. Similar to the function of the processor 404 in FIG. 4, when at least one of the cell voltage V _C1 ~ the cell voltage V _C3 is greater than the voltage threshold V _H or less than the voltage threshold V _L , the processor 504 begins It is detected whether or not the battery unit C1 to the battery unit C3 are unbalanced, and the battery unit C1 to the battery unit C3 are equalized when an imbalance is detected. In the embodiment shown in FIG. 5, the processor 504 can perform an equalization operation to adjust the cell voltage V _C1 to the cell voltage V _C3 of the battery cells _C1 to _C3 to a predetermined value. More specifically, in one embodiment of the present invention, when the battery is charged, the processor 504 provides a voltage equal to or greater than the threshold voltage V _H of the threshold V _TH. For a single battery unit, processor 504 charges it until the battery cell voltage of this battery unit reaches voltage threshold _VTH . In one embodiment of the invention, processor 504 receives comparison signal 531, comparison signal 532, and comparison signal 533. If the comparison signal 531 to the comparison signal 533 indicate that one of the battery cell voltage V _C1 to the battery cell voltage V _C3 of the corresponding battery cell C1 to the battery cell C3 reaches the voltage threshold V _TH , the processor 504 generates an equalization. Signal 480 is coupled to a bypass circuit that is coupled to the battery unit. Therefore, the charging of the battery unit is ended, but the other battery units are continuously charged. When the cell voltage of a battery cell reaches the voltage threshold _VTH , the corresponding bypass circuit in the equalization circuit 401 (eg, the bypass circuit includes a series of switches and resistors) is turned on. When the cell voltage V _C1 ~ cell voltage V _C3 both reach the voltage threshold V _TH , the equalization operation stops. Therefore, the equalization operation of the battery unit is completed.

For example, when the cell voltage V C1 of the battery cell _{C1 is} greater than the voltage threshold V _H , the comparator 541 compares the cell voltage V _C1 with the voltage threshold V _TH . If the comparison signal 531 indicates that the battery cell voltage V _C1 reaches the voltage threshold V _TH , the processor 504 generates an equalization signal 480 to turn on the switch S1. Therefore, the charging current I _CHARGE flows through the switch S1, the battery unit C2, and the battery unit C3. Therefore, the charging current I _CHARGE charges only the battery unit C2 and the battery unit C3. The charging process of the battery unit C1 ends. Similarly, when the cell voltage V _C2 and the cell voltage V _C3 reach the voltage threshold V _TH , the switch S2 and the switch S3 are turned on correspondingly. Therefore, the cell voltage V _C1 to the cell voltage V _{C3 are} adjusted to the voltage threshold V _TH to equalize the cell C1 to the cell C3.

In another embodiment of the invention, processor 504 executes programmable instructions to perform a comparison operation. For example, processor 504 compares digital signal 540 indicating battery cell voltage V _C1 ~ cell voltage V _C3 to voltage threshold V _TH . Therefore, in the present embodiment, the hardware comparator 541 to the comparator 543 can be omitted.

6 is a block diagram 600 of a battery system in accordance with yet another embodiment of the present invention. FIG. 6 will be described in conjunction with FIGS. 2 to 5. The components labeled the same as in Fig. 2 in Fig. 6 have similar functions.

In still another embodiment of the present invention, the battery system includes a battery pack 609, and the battery pack 609 includes a battery module 601 and a battery module 602. Although the battery pack 609 includes two battery modules in the embodiment shown in FIG. 6, the present invention is not limited thereto, and the battery pack 609 may also include other numbers of battery modules. Each battery module contains a known number of battery cells. For example, the battery module 601 includes battery cells C1 to C3, and the battery module 602 includes battery cells C4 to C6.

The battery module 601 and the battery module 602 are coupled to the equalization module 611 and the equalization module 612, respectively. The equalization module 611 and the equalization module 612 have a similar structure to the equalization module 510 shown in FIG. If an imbalance occurs, the cell voltage V _C1 to the cell voltage V _C6 of the battery cells _C1 to _{C6 are} adjusted to the voltage threshold V _TH . In another embodiment of the present invention, the battery module 601 and the equalization module 611 are disposed in one battery pack, and the battery module 602 and the equalization module 612 are disposed in another battery pack. Since each of the cell voltages V _C1 to V _C6 is adjusted to V _TH , it is also possible to equalize the cells in different battery packs.

7 is a flow chart 700 of an equalization method for a battery system in accordance with an embodiment of the present invention. FIG. 7 will be described in conjunction with FIGS. 2 to 6. The specific steps disclosed in Figure 7 are merely examples. In other words, the invention is equally applicable to other different steps or to the improved steps of Figure 7.

In step 701, the battery cells (eg, battery cells C1 - C3) are charged by a charging current (eg, charging current I _CHARGE ) and have corresponding battery cell voltages (eg, cell voltage V _C1 ~ cell voltage) V _C3 ).

In step 702, a first voltage threshold (eg, voltage threshold V _H or voltage threshold V _L ) is set according to the magnitude of the charging current (eg, charging current I _CHARGE ) in the constant current charging mode.

In step 703, when one of the plurality of battery cell voltages does not satisfy the first voltage threshold requirement, an equalization check of the battery cells is initiated. In one embodiment of the invention, the equalization check is initiated when one of the cell voltage V _C1 ~ cell voltage V _C3 is greater than the voltage threshold V _H . In one embodiment of the invention, the equalization check is initiated when one of the cell voltage V _C1 ~ cell voltage V _C3 is less than the voltage threshold V _L . In one embodiment of the invention, the equalization check is initiated when one of the battery cell voltages V _C1 to V _C3 is greater than the voltage threshold V _H or less than the voltage threshold V _L . Processor 404 or processor 504 provides voltage threshold V _H and voltage threshold V _L based on charging current I _CHARGE .

In step 704, each of the plurality of battery cell voltages (eg, cell voltage V _C1 ~ cell voltage V _C3 ) and a second voltage threshold (eg, voltage threshold V _TH ) Comparison is made and a plurality of comparison signals (eg, comparison signal 531 to comparison signal 533) are generated.

In step 705, the battery cells are equalized based on the comparison signals to adjust each battery cell voltage to a second voltage threshold.

The above detailed description and the accompanying drawings are only typical embodiments of the invention. It is apparent that various additions, modifications and substitutions are possible without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood by those of ordinary skill in the art that the present invention may be in the form of the form, structure, arrangement, ratio, material, element, element and other aspects in the actual application without departing from the invention. Changed. Therefore, the embodiments disclosed herein are intended to be illustrative and not limiting, and the scope of the invention is defined by the scope of the appended claims and their legal equivalents.

205‧‧‧Charger

210‧‧‧Equilibrium Module

290‧‧‧Charging pathway

400‧‧‧System block diagram of a battery system according to an embodiment of the present invention

401‧‧‧Equilibrium circuit

402‧‧‧Monitoring circuit

403‧‧‧ Analog Digital Converter

404‧‧‧ processor

411‧‧‧resistance

421~423, 460‧‧‧ monitoring signals

440‧‧‧ digital signal

470‧‧‧Control instructions

480‧‧‧balanced signal

Claims (18)

A battery system comprising: a plurality of battery cells having a plurality of battery cell voltages; and an equalization module coupled to the plurality of battery cells, according to a charging current setting of the plurality of battery cells in a constant current charging mode a first voltage threshold, and when a battery cell voltage of the plurality of battery cell voltages does not meet the requirement of the first voltage threshold, initiating an equalization check of the plurality of battery cells; wherein The equalization module includes: a processor that reads a data set, the data set indicates a change of a battery cell voltage when the battery unit is charged by the charging current, and the processor further determines a platform voltage region of the data set, And selecting the first voltage threshold according to the platform voltage region, wherein a cell voltage increase rate of the platform voltage region is less than a rate threshold. The battery system of claim 1, wherein the equalization check is initiated when one of the plurality of battery cell voltages is greater than the first voltage threshold. The battery system of claim 1, wherein the equalization check is initiated when one of the plurality of battery cell voltages is less than the first voltage threshold. The battery system of claim 1, wherein the processor sets the first voltage threshold to be greater than a maximum battery voltage when the battery unit operates in the platform voltage region. The battery system of claim 1, wherein the processor sets the first voltage threshold to be less than a minimum cell voltage when the battery cell operates in the platform voltage region. The battery system of claim 1, wherein the equalization module further comprises: And comparing, by the plurality of comparators, each of the plurality of battery cell voltages with a second voltage threshold and generating a plurality of comparison signals; and equalizing the plurality of battery voltages according to the plurality of comparison signals And adjusting each of the plurality of battery cell voltages to the second voltage threshold. The battery system of claim 6, wherein the second voltage threshold is greater than or equal to the first voltage threshold. A battery charging method includes: charging a plurality of battery cells, the plurality of battery cells having a plurality of battery cell voltages; setting a first voltage threshold according to a charging current in a constant current charging mode; When one of the plurality of battery cell voltages does not meet the requirement of the first voltage threshold, initiating an equalization check of the plurality of battery cells; reading a data set indicating that a battery unit is a change in battery cell voltage during charging of the charging current; determining a platform voltage region of the data set, a cell voltage increase rate of the platform voltage region being lower than a rate threshold; and setting the voltage region according to the platform The first voltage threshold. The battery charging method of claim 8, further comprising: starting the equalization check when one of the plurality of battery cell voltages is greater than the first voltage threshold. The battery charging method of claim 8, further comprising: starting the equalization check when one of the plurality of battery cell voltages is less than the first voltage threshold. For example, the battery charging method of claim 8 of the patent scope also includes: The first voltage threshold is set to be greater than a maximum cell voltage value when the battery cell operates in the platform voltage region. The battery charging method of claim 8, further comprising: setting the first voltage threshold to be smaller than a minimum battery voltage value when the battery unit operates in the platform voltage region. The battery charging method of claim 8, further comprising: comparing each of the plurality of battery cell voltages with a second voltage threshold value, and generating a plurality of comparison signals; The plurality of comparison signals equalize the plurality of battery cells to adjust the voltage of each of the plurality of battery cell voltages to the second voltage threshold. A battery system comprising: a plurality of battery modules connected in series, wherein each of the plurality of battery modules comprises a plurality of battery cells, the plurality of battery cells having a plurality of battery cell voltages; and a plurality of equalizations The module is coupled to the plurality of battery modules, wherein each of the plurality of equalization modules sets a first voltage according to a charging current of the plurality of battery cells in a constant current charging mode Limiting, and when a battery cell voltage of the plurality of battery cell voltages does not meet the requirement of the first voltage threshold, initiating an equalization check of the plurality of battery cells, wherein the plurality of equalization modules Each of the equalization modules includes: a processor that reads a data set, the data set indicates a change in a battery cell voltage when a battery unit is charged by the charging current, and the processor further determines one of the data sets a platform voltage region, and selecting the first voltage threshold according to the platform voltage region, wherein a cell voltage increase rate of the platform voltage region is less than a rate threshold. The battery system of claim 14, wherein the equalization check is initiated when one of the plurality of battery cell voltages is greater than the first voltage threshold. The battery system of claim 14, wherein the equalization check is initiated when one of the plurality of battery cell voltages is less than the first voltage threshold. The battery system of claim 14, wherein each of the equalization modules further comprises: a plurality of comparators coupled to the plurality of battery cells, each of the plurality of battery cell voltages Comparing with a second voltage threshold, and generating a plurality of comparison signals, and further equalizing the plurality of battery cells according to the plurality of comparison signals to adjust each of the plurality of battery cell voltages to the The second voltage threshold. The battery system of claim 17, wherein the plurality of equalization modules are provided with a plurality of equal second voltage thresholds.