TWI686034B - A monitoring device for a multi-cell battery pack - Google Patents

Abstract

A monitoring device for a multi-cell battery pack is disclosed. The device includes the multi-cell battery pack, a voltage measuring unit, a current measuring unit, a switch driving unit and a controller unit. The controller unit which electrically connected with the voltage measuring unit, the current measuring unit and the switch driving unit, respectively is adopted to obtain a first battery model or a second battery model according to a first breakover voltage and a first open circuit voltage, or a second breakover voltage and a second open circuit voltage measured by the voltage measuring unit, and a first and second breakover currents measured by the current measuring unit. Therefore, the multi-cell battery pack could be monitored and supply an electrical power stably while obtaining the first and second battery models thereof.

Description

Multi-cell battery monitoring device

The invention relates to a battery monitoring device, in particular to a multi-cell battery monitoring device.

Batteries are widely used in various types of electronic products, and usually use a multi-cell battery structure, that is, multiple batteries connected in series or parallel to supply the power required for the operation of electronic products. The charging/discharging circuit of the multi-cell battery is formed by the controller controlling the switching circuit. For example, when the battery in the charging/discharging circuit is switched to a new offline battery, and the original offline battery is added to the charging/discharging circuit, the controller may disconnect the series switch connected to the switching circuit of the new offline battery, and The bypass switch is turned on, so that the new offline battery will not be charged or discharged, and the bypass switch connected to the switching circuit of the original offline battery is turned off, and then the series switch is turned on, so that the original offline battery is added to the charging/discharging circuit Charge or discharge.

At present, multi-cell battery packs are used to obtain the battery power by measuring the voltage or current of the "battery in operation" (through a resistor in series) or a combination of the two. And current to calculate the battery power, but any battery in this method cannot be completely offline from the battery pack, otherwise it cannot continue to supply power to the battery pack. When the load draws current from the battery pack, the voltage of the battery will therefore float. The main reason for this floating is that the actual battery model is a real battery electromotive force (emf) and a battery internal resistance (internal resistance) , When the current flows through the battery, the internal resistance will cause a voltage drop. The measured battery terminal voltage includes this voltage drop, but the internal resistance of each battery is unknown, and the current is floating, so it is difficult to obtain the real battery emf , Meaning that the battery charge cannot be accurately calculated.

After obtaining the voltage and current of the battery, the power of the battery can be calculated. At present, there are the open circuit voltage method and the Coulomb measurement method. The open circuit voltage method is a traditional architecture, so it is not easy to obtain the open circuit voltage (open circuit voltage). Although there is also a dynamic open circuit voltage method that approximates the open circuit voltage through the battery's breakover voltage, it requires complex iterative calculations. And it is only an approximate approach. The Coulomb measurement method accumulates errors with time and current, which is usually inaccurate due to current sensing errors and battery state-of-charge estimation due to battery self-discharge. Even if the current sensing error is very small, the coulomb counter will continue to accumulate the error, and the accumulated error can only be eliminated when fully charged or fully discharged.

In addition, because the voltage output of a multi-cell battery pack when going offline or when switching is added, the voltage of a battery usually rises or falls, and even a brief voltage loss occurs, resulting in the multi-cell battery pack being unable to stabilize the output voltage and affecting the power supply. Quality, so that electronic products must additionally use larger capacitors to store charge, or additional voltage regulator circuits or balancing circuits must be added to the multi-cell battery pack, so as to stabilize the output voltage of the multi-cell battery pack, but this method is usually It will increase the cost of multi-cell battery packs or electronic products, and the circuit will be complicated.

In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a monitoring device for a multi-cell battery pack that can save costs, simplify circuits, and stabilize output voltage. The monitoring device of the multi-cell battery pack of the present invention can enable some batteries in the multi-cell battery pack to be temporarily offline at the time of switching and can also maintain the complete power supply of the battery pack. At this time, the off-line battery can measure its open circuit voltage. No current flows through the internal resistance of the battery, so it can represent the real battery electromotive force and can effectively judge the battery's charge. By switching one by one, you can get the power of each battery in the battery pack. In addition, the monitoring device of the multi-cell battery pack of the present invention can obtain the internal resistance of the battery through the voltage change of the battery before and after offline and cooperate with the current measurement unit, and then obtain the life of the battery. The power supply circuit of the multi-cell battery pack of the present invention can stably supply power to the load or electronic products during the above switching process, and can accurately measure and calculate the power of each battery in the multi-cell battery pack without any additional measurement circuit Power and life.

To achieve the above object, the present invention provides a monitoring device for a multi-cell battery pack, which includes: A multi-cell battery pack is electrically connected to a load. The multi-cell battery pack includes: A power supply loop, which is used to provide a loop voltage to the load; A first battery, coupled to a first series switch and a first bypass switch, and electrically connected to the power supply circuit using the first series switch or the first bypass switch; and A second battery, coupled to a second series switch and a second bypass switch, and electrically connected to the power supply circuit by using the second series switch or the second bypass switch; A voltage measuring unit, electrically connected to the multi-cell battery pack, for measuring a first turn-on voltage and a first open-circuit voltage of the first battery or a second turn-on voltage and a of the second battery, respectively Second open circuit voltage; A current measurement unit, electrically connected to the multi-cell battery pack, for respectively measuring a first conduction current of the first battery or a second conduction current of the second battery; A switch drive unit, electrically connected to the multi-cell battery pack, for driving the first series switch coupled to the first battery, the first bypass switch, and the second series switch coupled to the second battery , The second bypass switch is off or on; and A control unit, which is electrically connected to the voltage measuring unit, the current measuring unit and the switch driving unit, respectively, and is used for according to the first on voltage and the first open circuit voltage measured by the voltage measuring unit or The second turn-on voltage and the second open-circuit voltage, and the first turn-on current or the second turn-on current measured by the current measuring unit to obtain a first battery model of the first battery or the second One of the batteries, the second battery model; Wherein, during the process of obtaining the first battery model of the first battery or the second battery model of the second battery, the control unit can simultaneously monitor and maintain the circuit of the power supply circuit Voltage to supply power to the load stably.

Furthermore, in order to achieve the above object, when the first battery and the second battery of the monitoring device of the present invention are electrically connected to the power supply circuit by using the first series switch and the second series switch, respectively, the voltage measuring unit and the second battery The current measuring unit measures the first on-voltage and the first on-current of the first battery, and the second on-voltage and the second on-current of the second battery, respectively.

In addition, in order to achieve the above object, when the first battery and the second battery of the monitoring device of the present invention are electrically connected to the power supply circuit using the first bypass switch and the second bypass switch, respectively, the voltage measurement The unit separately measures the first open circuit voltage of the first battery and the second open circuit voltage of the second battery.

Moreover, in order to achieve the above object, the control unit of the monitoring device of the present invention obtains the first battery model of the first battery based on the first on-voltage, the first open-circuit voltage and the first on-current of the first battery .

Moreover, in order to achieve the above object, the control unit of the monitoring device of the present invention obtains the second battery model of the second battery based on the second on-voltage, the second open-circuit voltage and the second on-current of the second battery .

In addition, to achieve the above object, the first battery model of the monitoring device of the present invention is at least one of a first internal resistance and a first electromotive force of the first battery.

Moreover, in order to achieve the above object, the first internal resistance and the first electromotive force of the first battery model of the monitoring device of the present invention are used to calculate both the first battery capacity and the first battery life of the first battery At least one.

Moreover, in order to achieve the above object, the second battery model of the monitoring device of the present invention is at least one of a second internal resistance and a second electromotive force of the second battery.

Moreover, in order to achieve the above object, the second internal resistance and the second electromotive force of the second battery model of the monitoring device of the present invention are used to calculate both the second battery power and the second battery life of the second battery At least one.

Moreover, in order to achieve the above object, the switch driving unit of the monitoring device of the present invention drives the first series switch coupled to the first battery, the first bypass switch, and the second battery coupled to the The disconnection or conduction of the second series switch and the second bypass switch causes the first battery and the second battery to switch to each other in the power supply circuit.

Moreover, to achieve the above object, the control unit of the monitoring device of the present invention is based on the first on-voltage or the first open circuit voltage of the first battery, and the second on-voltage or the second open circuit of the second battery Voltage to control the switch drive unit.

Moreover, to achieve the above object, the control unit of the monitoring device of the present invention controls the switch drive unit according to at least one of the first battery model of the first battery and the second battery model of the second battery .

Moreover, to achieve the above object, the control unit of the monitoring device of the present invention controls the switch drive unit according to at least one of the first battery power of the first battery and the second battery power of the second battery .

Moreover, to achieve the above object, the control unit of the monitoring device of the present invention controls the switch drive unit based on at least one of the first battery life of the first battery and the second battery life of the second battery .

In addition, in order to achieve the above object, the control unit of the monitoring device of the present invention is a Microcontroller Unit (MCU), a Personal Computer (PC), and a Programmable Logic Controller (PLC) Or a Field-Programmable Gate Array (FPGA).

With the multi-cell battery monitoring device of the present invention, users can use simpler hardware components, including but not limited to multi-cell batteries, voltage measurement units, current measurement units, switch drive units, and control units. Therefore, the required cost is lower, the detection response and the switching speed are faster, and at the same time, the voltage change range of the battery switching moment of the multi-cell battery pack can be reduced. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, preferred embodiments are described below in conjunction with the accompanying drawings, which are described in detail below. However, those of ordinary knowledge in the field of the present invention should be able to understand that these detailed descriptions and specific embodiments listed for implementing the present invention are only used to illustrate the present invention, and are not intended to limit the scope of the patent application of the present invention.

Hereinafter, the preferred embodiments made according to the present invention will be listed in conjunction with the drawings to explain the constituent members and the achieved effects disclosed by the present invention. However, the components, dimensions, and appearance of the menu setting device shown in the drawings are only used to illustrate the technical features of the present invention, and do not limit the present invention.

First, please refer to FIG. 1, which is a schematic diagram of the composition block of the multi-cell battery monitoring device according to the present invention and the power supply circuit before switching. The monitoring device 1 of the multi-cell battery pack of the present invention is used to stably supply power to a load 3. The load 3 includes, but is not limited to, portable computers, mobile phones, electric vehicles, electric vehicles or portable small household appliances. Power supply to operate electronic product equipment. The monitoring device 1 of the present invention includes a multi-cell battery 5, a voltage measuring unit 7, a current measuring unit 9, a switch driving unit 11, and a control unit 13. The multi-cell battery pack 5 of the monitoring device 1 of the present invention is electrically connected to the load 3 and includes a first battery 15 and a second battery 17. The multi-cell battery pack 5 is exemplified as a series battery pack composed of three batteries, and a power supply loop L1 formed therefrom is used to provide a loop voltage (not shown) to the load 3. The first battery 15 is coupled to a first series switch 19 and a first bypass switch 21, which are electrically connected to the power supply circuit L1 by using the first series switch 19 or the first bypass switch 21 (for example, FIG. 1 uses The first series switch 19 is electrically connected to the power supply circuit L1); the second battery 17 is coupled to a second series switch 23 and a second bypass switch 25, which utilizes the second series switch 23 or the second bypass switch 25 It is electrically connected to the power supply circuit L1 (for example, in FIG. 1, the second bypass switch 25 is used to electrically connect to the power supply circuit L1, for example). The first series switch 19 and the first bypass switch 21 coupled to the first battery 15 and the second series switch 23 and the second bypass switch 25 coupled to the second battery 17 may be, for example, transistors, diodes or diodes The composition.

Please refer to Figures 1 and 2 at the same time. Figure 2 is a schematic diagram of the first and second battery models obtained by the monitoring device of the multi-cell battery pack of the present invention. The monitoring device 1 of the present invention further includes a voltage measuring unit 7 and a current measuring unit 9 electrically connected to the multi-cell battery 5. The voltage measuring unit 7 can be used to measure a first conduction voltage Vbc1 and a first open circuit voltage Voc1 of the first battery 15 or a second conduction voltage Vbc2 and a second open circuit voltage Voc2 of the second battery 17, respectively. The current measuring unit 9 measures the first conducting current I1 of one of the first batteries 15 or the second conducting current I2 of one of the second batteries 17, respectively. It can be seen from FIG. 1 that the voltage measuring unit 7 measures the first conduction voltage Vbc1 of the first battery 15 in the power supply circuit L1 (ie online) and the second voltage Vbc1 not in the power supply circuit L1 (ie offline) The second open circuit voltage Voc2 of the battery 17; the current measuring unit 9 measures the first on-current I1 of the first battery 15.

With continued reference to FIG. 1 as well, the switch drive unit 11 of the monitoring device 1 of the present invention is electrically connected to the multi-cell battery pack 5 to drive the first series switch 19 and the first bypass switch 21 coupled to the first battery 15, The second series switch 23 and the second bypass switch 25 coupled to the second battery 17 are turned off or turned on. The control unit 13 of the monitoring device 1 of the present invention is electrically connected to the voltage measuring unit 7, the current measuring unit 9 and the switch driving unit 11, respectively, and it is based on the voltage and voltage provided by the voltage measuring unit 7 and the current measuring unit 9 In the current situation, the switch drive unit 11 is used to select two batteries from the three batteries of the multi-cell battery pack 5 to form the power supply circuit L1, wherein the second battery 17 that is not allocated as the power supply circuit L1 is defined as an offline battery, an offline battery Can rest and wait to be assigned. Furthermore, if any of the three batteries occur during the power supply process, such as low voltage, the abnormal battery status can be measured by the voltage measuring unit 7 and turned into an offline battery to improve The safety of battery pack 5. Although the number of offline batteries is exemplified in the present invention, in practice, the number of offline batteries may be two or more. When the offline battery is designed to be two or more, those skilled in the art can still understand the total number of batteries of the multi-cell battery pack 5 through the description of the present invention.

Please also refer to Figures 2 and 3, where Figure 3 is a schematic diagram of the power supply circuit after switching according to Figure 1. It can be seen from FIG. 3 that when the first battery 15 and the second battery 17 after switching are electrically connected to the power supply circuit L2 by the first bypass switch 21 and the second series switch 23, the voltage measuring unit 7 measures The first open circuit voltage Voc1 to the first battery 15 not in the power supply loop L2 (ie offline), and the second conduction voltage Vbc2 of the second battery 17 in the power supply loop L2 (ie online); the current measuring unit 9 Then, the second conducting current I2 of the second battery 17 is measured.

故在第一電池15離線於供電迴路L2之情況下，仍可獲得第一電池15之第一內電阻R ₁，此即離線電池量測法。接著由第一電池15之第一內電阻R ₁及第一電動勢emf ₁可精確地計算一第一電池電量(圖未示)及一第一電池壽命(圖未示)二者至少其一。由於第一電池15之實際電量(圖未示)可透過第一電池電量及第一電池壽命計算獲得，即利用二者之乘積與第一電池15之初始最大電量(圖未示)相乘之後，即可獲得第一電池15之實際電量。相同地，控制單元13係根據第二電池17之第二導通電壓Vbc ₂、第二開路電壓Voc ₂與第二導通電流I ₂獲得第二電池模型BM2。第二電池模型BM2係第二電池17之一第二內電阻R ₂及一第二電動勢emf ₂二者至少其一，其中第二電動勢emf ₂可利用第二開路電壓Voc ₂量測而得，故第二電動勢emf ₂例如可以是第二開路電壓Voc ₂。由第二電池17之第二內電阻R ₂及第二電動勢emf ₂可用以精確地計算一第二電池電量(圖未示)及一第二電池壽命(圖未示)二者至少其一，進而獲得第二電池17之實際電量(圖未示)，關於第二電池17之說明與第一電池15相同，於此不再贅述。如此，本發明監控裝置1即可對多節電池組5之實際電量進行監控。 Please refer to FIGS. 1 to 3 at the same time. The control unit 13 of the monitoring device 1 of the present invention obtains a first battery model BM1 according to the first conduction voltage Vbc1 of the first battery 15, the first open circuit voltage Voc1 and the first conduction current I1. The first battery model BM1 is at least one of a first internal resistance R1 of a first battery 15 and a first electromotive force emf1, where the first electromotive force emf1 can be measured using the first open circuit voltage Voc1, Therefore, the first electromotive force emf1 may be, for example, the first open circuit voltage Voc1. The difference between the first conduction voltage Vbc1 and the first open circuit voltage Voc1 is caused by the first internal resistance R1 and the first conduction current I1 of the first battery 15, so the first internal resistance R1 can utilize the first conduction voltage Vbc1 and The ratio between the difference between the first open circuit voltage Voc1 and the first on current I1 is obtained, that is:

Therefore, when the first battery 15 is offline to the power supply circuit L2, the first internal resistance R _{1 of the} first battery 15 can still be obtained, which is the offline battery measurement method. Then, at least one of a first battery charge (not shown) and a first battery life (not shown) can be accurately calculated from the first internal resistance R ₁ and the first electromotive force emf _{1 of the} first battery 15. Since the actual power of the first battery 15 (not shown) can be obtained by calculating the first battery power and the first battery life, that is, after the product of the two is multiplied by the initial maximum power of the first battery 15 (not shown) , You can get the actual power of the first battery 15. Similarly, the control unit 13 obtains the second battery model BM2 based on the second on-voltage Vbc ₂ , the second open-circuit voltage Voc ₂ and the second on-current I _{2 of the} second battery 17. The second battery model BM2 is at least one of a second internal resistance R ₂ and a second electromotive force emf ₂ of the second battery 17, wherein the second electromotive force emf ₂ can be measured by using the second open circuit voltage Voc ₂ , Therefore, the second electromotive force emf ₂ may be, for example, the second open circuit voltage Voc ₂ . The second internal resistance R ₂ and the second electromotive force emf _{2 of the} second battery 17 can be used to accurately calculate at least one of a second battery charge (not shown) and a second battery life (not shown), Furthermore, the actual power of the second battery 17 (not shown) is obtained. The description of the second battery 17 is the same as that of the first battery 15 and will not be repeated here. In this way, the monitoring device 1 of the present invention can monitor the actual power of the multi-cell battery pack 5.

It can be seen from FIGS. 1 to 3 that the control unit 13 of the monitoring device 1 of the present invention is used to measure the first conduction voltage Vbc1 and the first open circuit voltage Voc1 or the second conduction voltage Vbc2 and the second measurement according to the voltage measurement unit 7. The open circuit voltage Voc2 and the first conducting current I1 or the second conducting current I2 measured by the current measuring unit 9 are used to obtain the first battery model BM1 of the first battery 15 or the second battery model BM2 of the second battery 17. During the process of obtaining the first battery model BM1 of the first battery 15 or the second battery model BM2 of the second battery 17, the control unit 13 can simultaneously monitor and maintain the circuit voltages of the power supply circuits L1, L2 , To stabilize the power supply to the load 3. The control unit 13 of the monitoring device 1 of the present invention may be a micro control unit (MCU), a personal computer (PC), a programmable logic controller (PLC) or a field programmable gate array (FPGA).

When the voltage measuring unit 7 of the monitoring device 1 of the present invention measures the first conduction voltage Vbc1 of two batteries (for example, one of them is the first battery 15) of the power supply circuit L1 (Figure 1) of the multi-cell battery pack 5 , The first open circuit voltage Voc1, the first battery model BM1, the first battery power or the first battery life and the second conduction voltage Vbc2, the second open circuit voltage Voc2, the second battery of the offline battery (such as the second battery 17), respectively When the result of the comparison between the model BM2, the second battery level or the second battery life meets a switching condition or a predetermined value, the switch driving unit 11 drives the first series switch 19 and the first serial switch 19 coupled to the first battery 15 according to the control unit 13 A bypass switch 21 and a second series switch 23 and a second bypass switch 25 coupled to the second battery 17 are disconnected or turned on, so that the first battery 15 and the second battery 17 are mutually switched in the power supply circuit L1, The power supply circuit L2 of the multi-cell battery 5 shown in FIG. 3 is formed. When the switch driving unit 11 switches the first battery 15 to the first bypass switch 21 coupled by the first battery 15 and is electrically connected to the power supply circuit L2, the second battery 17 is switched to the second coupled by the second battery 17 After the series switch 23 is electrically connected to the power supply circuit L2, the first battery 15 in the multi-cell battery pack 5 is cut off from the power supply circuit L2, and the second battery 17 is cut into the power supply circuit L2, and can maintain the power supply circuit L1. The loop voltage of L2 enables the multi-cell battery pack 5 to supply power to the load 3 stably during the switching between the first battery 15 and the second battery 17. When the two batteries of the power supply circuit L2 (Figure 3) of the multi-cell battery pack 5 are compared with the offline battery (such as the first battery 15) and the switching conditions are met again, the power supply circuit L2 two is selected again. One of the batteries is disconnected from the power supply circuit L2, and an offline battery (for example, the first battery 15) is added to the power supply circuit L2. Repeat the above electrical measurement and detection actions to obtain multiple cells The power and life of each battery in the battery pack 5 are further monitored.

Since the time required for the switch driving unit 11 of the present invention to perform switching is very small, the offline battery in the power supply circuit L1 of the multi-cell battery pack 5 can be quickly switched from the second battery 17 to the first battery 15. Moreover, during the switching process of the switch driving unit 11, the voltages of the power supply circuits L1, L2 of the multi-cell battery pack 5 can be maintained, so in addition to accurately calculating the battery power and battery life to obtain the actual battery power for monitoring, More stable power supply to load 3 or electronic products.

In summary, the multi-cell battery monitoring device disclosed in the present invention, when the multi-cell battery is charged and discharged, at least one battery is offline, and can be measured without affecting the characteristics of the multi-cell battery and the load The open circuit voltage of the offline battery is used to obtain the power and life of the multi-cell battery pack. Since the monitoring device of the multi-cell battery pack of the present invention can monitor the actual power of the multi-cell battery pack during the switching process, it can also maintain the voltage of the power supply loop, so that the multi-cell battery pack can stably supply power to the load during the battery switching process Or electronic products, there will be no abnormal output voltage.

Finally, it is emphasized that the constituent elements disclosed in the foregoing disclosed embodiments of the present invention are for illustration only, and are not intended to limit the scope of the present invention. The substitution or variation of other equivalent elements should also fall within the scope of the patent application of the present invention. Covered.

1‧‧‧Monitoring device L1, L2‧‧‧Power supply circuit 3‧‧‧ Load Vbc ₁ ‧‧‧ First conduction voltage 5‧‧‧ Multi-cell battery pack Voc ₁ ‧‧‧ First open circuit voltage 7‧‧‧ Voltage Measuring unit Vbc ₂ ‧‧‧ Second conducting voltage 9‧‧‧ Current measuring unit Voc ₂ ‧‧‧ Second open circuit voltage 11‧‧‧ Switch driving unit I ₁ ‧‧‧ First conducting current 13‧‧‧Control Unit I ₂ ‧‧‧ Second conduction current 15‧‧‧ First battery BM1‧‧‧ First battery model 17‧‧‧ Second battery R ₁ ‧‧‧ First internal resistance 19‧‧‧ First series switch emf ₁ ‧‧‧ First electromotive force 21 ‧‧‧ First bypass switch BM2 ‧‧‧ Second battery model 23 ‧‧‧ Second series switch R ₂ ‧‧‧ Second internal resistance 25‧‧‧ Second bypass switch emf ₂ ‧‧‧ Second electromotive force

Fig. 1 shows a block diagram of a multi-cell battery monitoring device according to the present invention and a schematic diagram of a power supply circuit before switching.

FIG. 2 shows a schematic diagram of the first and second battery models obtained by the monitoring device of the multi-cell battery pack of the present invention.

FIG. 3 shows a schematic diagram of the power supply circuit after the monitoring device of the multi-cell battery pack according to the present invention is switched.

1‧‧‧Monitoring device

3‧‧‧load

5‧‧‧Multi-cell battery pack

7‧‧‧Voltage measuring unit

9‧‧‧Current measurement unit

11‧‧‧Switch drive unit

13‧‧‧Control unit

15‧‧‧ First battery

17‧‧‧Second battery

19‧‧‧First series switch

21‧‧‧First bypass switch

23‧‧‧Second series switch

25‧‧‧ Second bypass switch

L1‧‧‧Power supply circuit

Claims (15)

A monitoring device for a multi-cell battery pack, including: A multi-cell battery pack is electrically connected to a load. The multi-cell battery pack includes: A power supply loop, which is used to provide a loop voltage to the load; A first battery, coupled to a first series switch and a first bypass switch, and electrically connected to the power supply circuit using the first series switch or the first bypass switch; and A second battery, coupled to a second series switch and a second bypass switch, and electrically connected to the power supply circuit by using the second series switch or the second bypass switch; A voltage measuring unit, electrically connected to the multi-cell battery pack, for measuring a first turn-on voltage and a first open-circuit voltage of the first battery or a second turn-on voltage and a of the second battery, respectively Second open circuit voltage; A current measurement unit, electrically connected to the multi-cell battery pack, for respectively measuring a first conduction current of the first battery or a second conduction current of the second battery; A switch drive unit, electrically connected to the multi-cell battery pack, for driving the first series switch coupled to the first battery, the first bypass switch, and the second series switch coupled to the second battery , The second bypass switch is off or on; and A control unit, which is electrically connected to the voltage measuring unit, the current measuring unit and the switch driving unit respectively, and is used for according to the first on-voltage and the first open-circuit voltage measured by the voltage measuring unit or The second conduction voltage and the second open circuit voltage, and the first conduction current or the second conduction current measured by the current measurement unit to obtain a first battery model of the first battery Or a second battery model of one of the second batteries; Wherein, during the process of obtaining the first battery model of the first battery or the second battery model of the second battery, the control unit can simultaneously monitor and maintain the circuit of the power supply circuit Voltage to supply power to the load stably. The monitoring device for a multi-cell battery pack according to claim 1, wherein when the first battery and the second battery are electrically connected to the power supply circuit using the first series switch and the second series switch, respectively, the voltage measuring unit And the current measuring unit respectively measure the first conduction voltage and the first conduction current of the first battery, and the second conduction voltage and the second conduction current of the second battery. The monitoring device of the multi-cell battery pack according to claim 1, wherein when the first battery and the second battery are electrically connected to the power supply circuit by using the first bypass switch and the second bypass switch, respectively, the voltage amount The measuring unit respectively measures the first open circuit voltage of the first battery and the second open circuit voltage of the second battery. The monitoring device for a multi-cell battery pack according to claim 1, wherein the control unit obtains the first of the first battery according to the first on-voltage, the first open-circuit voltage and the first on-current of the first battery Battery model. The monitoring device for a multi-cell battery pack according to claim 1, wherein the control unit obtains the second of the second battery according to the second on-voltage, the second open-circuit voltage and the second on-current of the second battery Battery model. A monitoring device for a multi-cell battery pack according to claim 1, wherein the first battery model is at least one of a first internal resistance (Eternal resistance) and a first electromotive force (emf) of the first battery . The monitoring device for a multi-cell battery pack according to claim 6, wherein the first internal resistance and the first electromotive force of the first battery model are used to calculate a first battery capacity and a first battery life of the first battery At least one of the two. The monitoring device for a multi-cell battery pack according to claim 1, wherein the second battery model is at least one of a second internal resistance and a second electromotive force of the second battery. The monitoring device for a multi-cell battery pack according to claim 8, wherein the second internal resistance and the second electromotive force of the second battery model are used to calculate a second battery power and a second battery life of the second battery At least one of the two. The monitoring device for a multi-cell battery pack according to claim 1, wherein the switch driving unit drives the first series switch of the first battery, the first bypass switch and the second of the second battery according to the control unit The series switch and the second bypass switch are turned off or turned on, so that the first battery and the second battery are mutually switched in the power supply circuit. The monitoring device for a multi-cell battery pack according to claim 10, wherein the control unit is based on the first on-voltage or the first open-circuit voltage of the first battery, and the second on-voltage or the first of the second battery Two open circuit voltages to control the switch drive unit. The monitoring device for a multi-cell battery pack according to claim 10, wherein the control unit controls the switch according to at least one of the first battery model of the first battery and the second battery model of the second battery Drive unit. The monitoring device for a multi-cell battery pack according to claim 10, wherein the control unit controls the switch based on at least one of a first battery level of the first battery and a second battery level of the second battery Drive unit. The monitoring device for a multi-cell battery pack according to claim 10, wherein the control unit controls the switch based on at least one of a first battery life of the first battery and a second battery life of the second battery Drive unit. For example, the monitoring device for multiple battery packs in claim 1, wherein the control unit is a microcontroller unit (MCU), a personal computer (PC), and a programmable logic controller (Programmable Logic Controller, PLC) or a Field-Programmable Gate Array (FPGA).

Images