Patent Description:
The described technology relates to a battery apparatus, a battery management system, and a method for diagnosing a connection status.

An electric vehicle or a hybrid vehicle is a vehicle that obtains power by driving a motor mainly using a battery as a power supply. The electric vehicles are being actively researched because they are alternatives that can solve pollution and energy problems of internal combustion vehicles. Rechargeable batteries are used in various external apparatuses other than the electric vehicles.

Recently, as a battery having a high output and a large charging capacity is required, a battery pack in which a plurality of battery modules are connected in series is used. Two adjacent battery modules in the battery pack are connected to each other via a bus-bar. An output terminal of the battery pack is connected via a wire to a switch that controls supply of a current to the battery pack.

Accordingly, when a problem occurs in the connection of the bus-bar or a problem occurs in the wire for connecting the battery pack and an external apparatus, power cannot be supplied through the battery pack. <CIT> relates to an apparatus that comprises: a pack voltage measuring unit which measures the voltage of the battery packs; a module voltage measuring unit which measures voltages of each battery module; and a control unit which conducts comparisons between the measured voltages of the battery modules and the battery packs, and determines whether or not the busbar is properly connected.

Some embodiments may provide a battery apparatus, a battery management system, and a method for diagnosing a connection status, for diagnosing a problem related to a connection status of the battery apparatus.

According to an aspect, a battery apparatus including a battery pack, a switch, a wire, a voltage measuring circuit, and a processor may be provided. The battery pack may include a plurality of battery modules and a bus-bar connecting two battery modules among the plurality of battery modules. The switch may control current supply of the battery pack, and the wire may connect the battery pack and the switch. The voltage measuring circuit may measure a voltage of the bus-bar, a voltage of the battery pack, and voltages of the plurality of battery modules. The processor may diagnose a connection status of the bus-bar and a connection status of the wire based on a current of the battery pack, the voltage of the bus-bar, the voltage of the battery pack, and the voltages of the plurality of battery modules.

In some embodiments, the processor may calculate a resistance of the bus-bar based on the voltage of the bus-bar and the current of the battery pack, and diagnose the connection status of the bus-bar based on the resistance of the bus-bar.

In some embodiments, in response to the resistance of the bus-bar being greater than a threshold, the processor may diagnose that an error has occurred in the connection status of the bus-bar.

In some embodiments, the processor may determine the voltage of the bus-bar based on a voltage between a node at which the bus-bar is connected to one of the two battery modules and a node at which the bus-bar is connected to the other one of the two battery modules.

In some embodiments, the processor may determine a voltage across the wire based on the voltage of the bus-bar, the voltage of the battery pack, and the voltages of the plurality of battery modules, calculate a resistance of the wire based on the voltage across the wire and the current of the battery pack, and diagnose the connection status of the wire based on the resistance of the wire.

In some embodiments, in response to the resistance of the wire being greater than a threshold, the processor may diagnose that an error has occurred in the connection status of the wire.

In some embodiments, the switch may include a first switch and a second switch, and the wire may include a first wire connecting a positive terminal of the battery pack and the first switch, and a second wire connecting a negative terminal of the battery pack and the second switch. In this case, the voltage across the wire may include a voltage across the first wire and a voltage across the second wire.

In some embodiments, the voltage measuring circuit may measure the voltage of the battery pack based on a voltage between a first node to which the first wire is connected to the first switch and a second node to which the second wire is connected to the second switch.

In some embodiments, the processor may determine the voltage across the wire based on a value obtained by subtracting a sum of the voltages of the plurality of battery modules and the voltage of the bus-bar from the voltage of the battery pack.

In some embodiments, the bus-bar may include a plurality of bus-bars, and each of the bus-bars may connect corresponding two battery modules among the plurality of battery modules. In this case, the processor may determine the voltage across the wire based on a value obtained by subtracting a sum of the voltages of the plurality of battery modules and a sum of voltages of the plurality of bus-bars from the voltage of the battery pack.

According to another aspect, a method of diagnosing a connection status of a battery pack including a plurality of battery modules may be provided. The method may include measuring a current of the battery pack, measuring a voltage of the battery pack, measuring a voltage of each of the plurality of battery modules, measuring a voltage of a bus-bar connecting two battery modules among the plurality of battery modules, and diagnosing a connection status of the bus-bar and a connection status of a wire connected to the battery pack, based on the current of the battery pack, the voltage of the bus-bar, the voltage of the battery pack, and voltages of the plurality of battery modules.

In some embodiments, the diagnosing the connection status may include calculating a resistance of the bus-bar based on the voltage of the bus-bar and the current of the battery pack, and diagnosing the connection status of the bus-bar based on the resistance of the bus-bar.

In some embodiments, the diagnosing the connection status may include determining a voltage across the wire based on the voltage of the bus-bar, the voltage of the battery pack, and the voltage of the plurality of battery modules, calculating a resistance of the wire based on the voltage across the wire and the current of the battery pack, and diagnosing the connection status of the wire based on the resistance of the wire.

In some embodiments, the wire may include a first wire connecting a positive terminal of the battery pack and a first switch for controlling current supply of the battery pack, and a second wire connecting a negative terminal of the battery pack and a second switch for controlling current supply of the battery pack. In this case, the measuring the voltage of the battery pack may include measuring the voltage of the battery pack based on a voltage between a first node to which the first wire is connected to the first switch and a second node to which the second wire is connected to the second switch.

According to yet another embodiment, a battery management system including the battery apparatus is provided.

According to some embodiments, a connection state of a bus-bar and a wire may be diagnosed in the battery apparatus.

In the following detailed description, only certain embodiments have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.

When it is described that an element is "connected" to another element, it should be understood that the element may be directly connected to the other element or connected to the other element through a third element. On the other hand, when it is described that an element is "directly connected" to another element, it should be understood that the element is connected to the other element through no third element.

As used herein, a singular form may be intended to include a plural form as well, unless the explicit expression such as "one" or "single" is used.

In flowcharts described with reference to the drawings, the order of operations or steps may be changed.

<FIG> is a diagram showing a battery apparatus according to an embodiment.

Referring to <FIG>, a battery apparatus <NUM> has a structure that can be electrically connected to an external apparatus through a positive link terminal DC(+) and a negative link terminal DC(-). In some embodiments, the battery apparatus <NUM> may be connected to the external apparatus <NUM> through the positive link terminal DC(+) and the negative link terminal DC(-). When the external apparatus is a load, the battery apparatus <NUM> is discharged by operating as a power supply that supplies power to the load. The external apparatus operating as the load may be, for example, an electronic device, a mobility apparatus, or an energy storage system (ESS). The mobility apparatus may be, for example, a vehicle such as an electric vehicle, a hybrid vehicle, or a smart mobility.

The battery apparatus <NUM> includes a battery pack <NUM>, a positive main switch <NUM>, a negative main switch <NUM>, a voltage measuring circuit <NUM>, a current sensor <NUM>, and a processor <NUM>.

The battery pack <NUM> has a positive terminal PV(+) and a negative terminal PV(-). The battery pack includes a plurality of battery modules (not shown) connected in series between the positive terminal PV(+) and the negative terminal PV(-), and each battery module includes a plurality of battery cells (not shown) connected in series. In some embodiments, the battery cell may be a rechargeable cell. In this way, the plurality of battery modules may be connected in the battery pack <NUM> to supply desired power.

The positive main switch <NUM> is connected between the positive terminal PV(+) of the battery pack <NUM> and the positive link terminal DC(+) of the battery apparatus <NUM>. The negative main switch <NUM> is connected between the negative terminal PV(-) of the battery pack <NUM> and the negative link terminal DC(-) of the battery apparatus <NUM>. The switches <NUM> and <NUM> may be controlled by the processor <NUM> to control an electrical connection between the battery pack <NUM> and the external apparatus. That is, the switches <NUM> and <NUM> may control supply of a current of the battery pack <NUM>. In one embodiment, each of the switches <NUM> and <NUM> may be a contactor implemented in a relay. In another embodiment, each of the switches <NUM> and <NUM> may be an electrical switch such as a transistor. In some embodiments, the battery apparatus <NUM> may further include driving circuits (not shown) for controlling the switches <NUM> and <NUM>, respectively.

The voltage measuring circuit <NUM> measures a voltage at a predetermined point in the battery apparatus <NUM>. The current sensor <NUM> measures the current of the battery pack <NUM>. In some embodiments, the current sensor <NUM> may measure a discharge current of the battery pack <NUM> (e.g., a current flowing from the positive terminal PV(+) of the battery pack <NUM> to the positive link terminal DC(+)) or a charging current of the battery pack <NUM> (e.g., a current flowing from the positive link terminal DC(+) to the positive terminal PV(+) of the battery pack <NUM>). Although the current sensor <NUM> is shown as being connected between the positive terminal PV(+) and the positive link terminal DC(+) of the battery pack in <FIG>, a position of the current sensor <NUM> is not limited thereto. For example, the current sensor <NUM> may be connected between the negative terminal PV(-) of the battery pack and the negative link terminal DC(-). In some embodiments, the current sensor <NUM> may be included in the battery pack <NUM>.

The processor <NUM> diagnoses a connection status of the battery apparatus <NUM> based on the voltage measured by the voltage measuring circuit <NUM> and the current measured by the current sensor <NUM>. In some embodiments, the processor <NUM> may control operations of the switches <NUM> and <NUM>. The processor <NUM> may be, for example, a micro controller unit (MCU).

The processor <NUM> may form a battery management system. In some embodiments, the battery management system may further include the voltage measuring circuit <NUM> or the current sensor <NUM>.

<FIG> is a diagram for explaining voltage measurement of a battery apparatus according to an embodiment, and <FIG> is a diagram showing an example of a bus-bar in a battery apparatus according to an embodiment.

Referring to <FIG>, a plurality of battery modules <NUM>, <NUM>, <NUM>, and <NUM> are connected in series in a battery pack <NUM>. Although four battery modules <NUM>, <NUM>, <NUM>, and <NUM> are shown in <FIG> for convenience of description, the number of battery modules is not limited thereto.

Two adjacent battery modules are connected via a bus-bar. A bus-bar <NUM> connects the battery module <NUM> and the battery module <NUM>, a bus-bar <NUM> connects the battery module <NUM> and the battery module <NUM>, and a bus-bar <NUM> connects the battery module <NUM> and the battery module <NUM>. A first terminal of the bus-bar <NUM> may be connected to a node BBP1 corresponding to a negative terminal of the battery module <NUM>, and a second terminal of the bus-bar <NUM> may be connected to a node BBN1 corresponding to a positive terminal of the battery module <NUM>. Further, a first terminal of the bus-bar <NUM> may be connected to a node BBP2 corresponding to a negative terminal of the battery module <NUM>, and a second terminal of the bus-bar <NUM> may be connected to a node BBN2 corresponding to a positive terminal of the battery module <NUM>. Furthermore, a first terminal of the bus-bar <NUM> may be connected to a node BBP3 corresponding to a negative terminal of the battery module <NUM>, and a second terminal of the bus-bar <NUM> may be connected to a node BBN3 corresponding to a positive terminal of the battery module <NUM>. In some embodiments, the positive terminal of each battery module may be connected to a positive electrode of the first battery cell among a plurality of battery cells, which are included in the corresponding battery module and are connected in series, and the negative terminal of each battery module may be connected to a negative electrode of the last battery cell among the plurality of battery cells, which are included in the corresponding battery module and are connected in series.

In some embodiments, the bus-bars <NUM>, <NUM>, and <NUM> may be formed of a material having electrical conductivity. The bus-bars <NUM>, <NUM>, and <NUM> may be formed in various shapes according to a structure of the battery pack <NUM> or the battery modules <NUM>, <NUM>, <NUM> and <NUM>. For example, as shown in <FIG>, the bus-bar <NUM> may be connected with an electrode terminal 211a of one battery module <NUM> and an electrode terminal 212a of the other battery module <NUM> so as to connect the battery module <NUM> and the battery module <NUM>. The electrode terminal 211a of the battery module <NUM> may be a negative terminal of the battery module <NUM>, and the electrode terminal 212a of the battery module <NUM> may be a positive terminal of the battery module <NUM>. As described above, since the bus-bar <NUM> is used for connecting the two battery modules, a current supplied from the battery apparatus may be interrupted when the connection is broken due to a defect in the connection status of the bus-bar.

The positive terminal PV(+) of the battery pack <NUM> is connected to a positive main switch <NUM> through a wire <NUM>, and the negative terminal PV(-) of the battery pack <NUM> is connected to a negative main switch <NUM> through a wire <NUM>. In this case, the wire <NUM> may be connected to the positive main switch <NUM> at a node W1, and the wire <NUM> may be connected to the negative main switch <NUM> at a node W2. In some embodiments, the positive terminal PV(+) of the battery pack <NUM> may correspond to a positive terminal of the first battery module <NUM> among the plurality of battery modules <NUM>, <NUM>, <NUM>, and <NUM> included in the battery pack <NUM>, and the negative terminal PV(-) of the battery pack <NUM> may correspond to a negative terminal of the last battery module <NUM> among the plurality of battery modules <NUM>, <NUM>, <NUM> and <NUM> included in the battery pack <NUM>. In some embodiments, the wires <NUM> and <NUM> may be provided as a wire harness.

When the positive main switch <NUM> and the negative main switch <NUM> are closed, a current Ipack flows through the battery pack <NUM>. That is, the current Ipack flows through the plurality of battery modules <NUM>, <NUM>, <NUM>, and <NUM>. In this case, a voltage measuring circuit <NUM> measures voltages of the bus-bars <NUM>, <NUM>, and <NUM>. The voltage measuring circuit <NUM> may measure a voltage between the first terminal and the second terminal of each bus-bar as the voltage of the corresponding bus-bar. That is, the voltage measuring circuit <NUM> may measure a voltage between the both terminals of the bus-bar <NUM>, i.e., a voltage between the two nodes BBP1 and BBN1, as a voltage of the bus-bar <NUM>, measure a voltage between the both terminals of the bus-bar <NUM>, i.e., a voltage between the two nodes BBP2 and BBN2, as a voltage of the bus-bar <NUM>, and measure a voltage between the both terminals of the bus-bar <NUM>, i.e., a voltage between the two nodes BBP3 and BBN3, as a voltage of the bus-bar <NUM>.

In some embodiments, the voltage measuring circuit <NUM> may include a cell voltage monitoring integrated circuit (IC). In some embodiments, a plurality of cell voltage monitoring ICs respectively corresponding to a plurality of battery modules may be provided. In some embodiments, one cell voltage monitoring IC may correspond to at least two battery modules among the plurality of battery modules. In some embodiments, one of the plurality of battery modules may correspond to two cell voltage monitoring ICs. In this case, one of the cell voltage monitoring ICs may correspond to some battery cells of the corresponding battery module, and the other one of the cell voltage monitoring ICs may correspond to the remaining battery cells of the corresponding battery module.

In some embodiments, the cell voltage monitoring IC may include a plurality of pins respectively connected to a plurality of battery cells of the battery module and two pins respectively connected to both terminals of the bus-bar. In this case, the cell voltage monitoring IC may measure the voltage of the bus-bar through the two pins respectively connected to both terminals of the bus-bar. Further, the cell voltage monitoring IC may measure a voltage of the battery cell through pins connected to the positive and negative electrodes of the battery cell.

The processor (e.g., <NUM> in <FIG>) may diagnose connection statuses of the bus-bars <NUM>, <NUM>, and <NUM> based on the voltages measured by the voltage measuring circuit <NUM>.

Next, a method of diagnosing a connection status in a battery apparatus according to various embodiments is described with reference to <FIG> and <FIG>.

<FIG> is a flowchart showing a method for diagnosing a connection status in a battery apparatus according to an embodiment.

Referring to <FIG>, a processor (e.g., <NUM> in <FIG>) of a battery management system closes a positive main switch (e.g., <NUM> in <FIG>) and a negative main switch (e.g., FIG. <NUM> in <FIG>). Then, a current flows through the battery pack (e.g., <NUM> in <FIG>). Accordingly, the processor <NUM> receives a current of the battery pack measured by a current sensor at S410.

Further, a voltage measuring circuit <NUM> measures a voltage of a bus-bar (e.g., <NUM>, <NUM>, or <NUM> in <FIG>) connecting adjacent battery modules at S420. In some embodiments, the voltage measuring circuit <NUM> may measure a voltage between both terminals of the bus-bar <NUM>, <NUM>, or <NUM> as the voltage of the bus-bar <NUM>, <NUM>, or <NUM>. The processor <NUM> receives the voltages of the bus-bars <NUM>, <NUM>, and <NUM> from the voltage measuring circuit <NUM> at S420.

Next, the processor <NUM> calculates a resistance of each of the bus-bars <NUM>, <NUM>, and <NUM> based on the current of the battery pack <NUM> and the voltage of each of the bus-bars <NUM>, <NUM>, and <NUM> at S430. In some embodiments, as shown in <FIG>, since the current of the battery pack <NUM> flows through the bus-bars <NUM>, <NUM>, and <NUM>, the voltage measuring circuit <NUM> may determine, as the resistance of each of the bus-bars <NUM>, <NUM>, and <NUM>, a value obtained by dividing the voltage of each of the bus-bars <NUM>, <NUM>, and <NUM> by the current of the battery pack <NUM>, as in Equation <NUM>.

In Equation <NUM>, Rbusbar denotes the resistance of the busbar, Vbusbar denotes the voltage of the busbar, and Ipack denotes the current of the battery pack.

The processor <NUM> diagnoses a connection status of the battery apparatus based on the resistance of each bus-bar and a resistance of a wire at S440. In some embodiments, the processor <NUM> may determine whether the resistance of each bus-bar is greater than a threshold, and if there is a bus-bar having the resistance greater than the threshold, the processor <NUM> may diagnose that an error has occurred in the connection status of the corresponding bus-bar. In some embodiments, when diagnosing that the error has occurred in the connection status of the bus-bar, the processor <NUM> may transmit an error signal to an external apparatus (e.g., a vehicle). Accordingly, a user (e.g., a driver) of the external apparatus may check the error and perform an action corresponding to the error.

On the other hand, as shown in <FIG>, in the battery pack <NUM>, an error may occur not only in the connection of the bus-bar, but also in a connection status of wires <NUM> and <NUM> connecting the battery pack <NUM> and the main switches <NUM> and <NUM>. Accordingly, it may not be possible to accurately diagnose the connection status of the battery apparatus only by diagnosing the connection status of the bus-bar.

<FIG> is a flowchart showing a method for diagnosing a connection status in a battery apparatus according to another embodiment.

Referring to <FIG>, a processor (e.g., <NUM> in <FIG>) of the battery management system closes a positive main switch (e.g., <NUM> in <FIG>) and a negative switch (e.g., FIG. <NUM> in <FIG>). Then, a current flows through a battery pack (e.g., <NUM> in <FIG>). Accordingly, the processor <NUM> receives a current of the battery pack measured by a current sensor at S510.

Further, a voltage measuring circuit (e.g., <NUM> in <FIG>) measures a voltage of a bus-bar (e.g., <NUM>, <NUM>, or <NUM> in <FIG>) connecting adjacent battery modules. In some embodiments, the voltage measuring circuit <NUM> may measure a voltage between both terminals of the bus-bar <NUM>, <NUM>, or <NUM> as the voltage of the bus-bar <NUM>, <NUM>, or <NUM>. The processor <NUM> receives the voltages of the bus-bars <NUM>, <NUM>, and <NUM> from the voltage measuring circuit <NUM> at S520.

Furthermore, the voltage measuring circuit <NUM> measures a voltage of the battery pack <NUM> and voltages of battery modules (e.g., <NUM>, <NUM>, <NUM>, and <NUM> in <FIG>) at S520. In some embodiments, the voltage measuring circuit <NUM> may measure the voltage of the battery pack <NUM> by measuring voltages of nodes at which wires (e.g., <NUM> and <NUM> in <FIG>) of the battery pack <NUM> are connected to the main switches (e.g., <NUM> and <NUM> in <FIG>). In some embodiments, the voltage measuring circuit <NUM> may measure a voltage between a positive terminal and a negative terminal of each battery module as the voltage of the corresponding battery module. In some embodiments, the voltage measuring circuit <NUM> may measure the voltage of each battery module as a sum of voltages of a plurality of battery cells included in the corresponding battery module. The processor <NUM> receives the voltage of the battery pack <NUM> and the voltages of the battery modules from the voltage measuring circuit <NUM> at S520.

The processor <NUM> calculates a resistance of each of the bus-bars <NUM>, <NUM>, and <NUM> based on the current of the battery pack <NUM> and the voltage of each of the bus-bars <NUM>, <NUM>, and <NUM> at S530. In some embodiments, the processor <NUM> may calculate the resistance of each of the bus-bars <NUM>, <NUM>, and <NUM> as described with reference to S430 of <FIG>.

Further, the processor <NUM> calculates a voltage across the wires <NUM> and <NUM> based on the current of the battery pack <NUM>, the voltage of the battery pack <NUM>, and the voltages of the battery modules <NUM>, <NUM>, <NUM> and <NUM> at S540. In some embodiments, the voltage measuring circuit <NUM> may measure the voltage of the battery pack <NUM> by measuring a voltage of a node (e.g., W1 in <FIG>) at which the wire <NUM> is connected to the positive main switch <NUM> and a voltage of a node (e.g., W2 in <FIG>) at which the wire <NUM> is connected to the negative main switch <NUM>. That is, the voltage measuring circuit <NUM> may measure a voltage between the two nodes W1 and W2 as the voltage of the battery pack <NUM>. In some embodiments, as shown in <FIG>, the voltage of the battery pack <NUM>, i.e., the voltage between the two nodes W1 and W2 is formed by the voltage across the wires <NUM> and <NUM>, the voltages of the battery module <NUM>, <NUM>, <NUM>, and <NUM>, and the voltages of the bus-bars <NUM>, <NUM>, and <NUM>, the processor <NUM> may determine, as the voltage across the two wires <NUM> and <NUM>, a value obtained by subtracting the voltages of the battery modules <NUM>, <NUM>, <NUM>, and <NUM>, and the voltages of the bus-bars <NUM>, <NUM>, and <NUM> from the voltage of the battery pack <NUM>, as in Equation <NUM>.

In Equation <NUM>, Vwire denotes the voltage across the two wires, Vpack denotes the voltage of the battery pack, Vmodule(i) denotes the voltage of the i-th battery module, N denotes the number of battery modules included in the battery pack, Vbusbar(i) denotes the voltage of the i-th bus-bar, and M denotes the number of bus-bars included in the battery pack. In some embodiments, M may be equal to (N-<NUM>).

Furthermore, the processor <NUM> calculates a resistance of the wires <NUM> and <NUM> based on the current of the battery pack <NUM> and the voltage across the wires <NUM> and <NUM> at S550. In some embodiments, since the current of the battery pack <NUM> flows through the wires <NUM> and <NUM> as shown in <FIG>, the voltage measuring circuit <NUM> may determine, as the resistance of the two wires <NUM> and <NUM>, a value obtained by dividing the voltage across the wires <NUM> and <NUM> by the current of the battery pack <NUM>.

In Equation <NUM>, Rwire denotes the resistance of the two wires, Vwire denotes the voltage across the two wires, and Ipack denotes the current of the battery pack.

The processor <NUM> diagnoses a connection status of the battery apparatus based on the resistance of each bus-bar and the resistance of the wires at S560. In some embodiments, the processor <NUM> may determine whether the resistance of each bus-bar is greater than a threshold, and if there is a bus-bar having the resistance greater than the threshold, the processor <NUM> may diagnose that an error has occurred in the connection status of the corresponding bus-bar. Further, the processor <NUM> may determine whether the resistance of the wires is greater than a threshold, and if the resistance of the wires is greater than the threshold value, the processor <NUM> may diagnose that an error has occurred in the connection status of the wires. In some embodiments, when diagnosing that the error has occurred in the connection status of the bus-bar or wires, the processor <NUM> may transmit an error signal to an external apparatus (e.g., a vehicle). Accordingly, a user (e.g., a driver) of the external apparatus may check the error and perform an action corresponding to the error.

According to the above-described embodiments, not only the connection status of the bus-bar but also the connection status of the wires connecting the battery pack to the main switches can be diagnosed, so that the connection status of the battery apparatus can be accurately diagnosed.

Claim 1:
A battery apparatus (<NUM>) comprising:
a battery pack (<NUM>, <NUM>) including a plurality of battery modules (<NUM>, <NUM>, <NUM>, <NUM>) and a bus-bar (<NUM>, <NUM>, <NUM>) connecting two battery modules among the plurality of battery modules (<NUM>, <NUM>, <NUM>, <NUM>);
a switch (<NUM>, <NUM>, <NUM>, <NUM>) configured to control current supply of the battery pack (<NUM>, <NUM>);
a wire (<NUM>, <NUM>) connecting the battery pack (<NUM>, <NUM>) and the switch (<NUM>, <NUM>, <NUM>, <NUM>);
a voltage measuring circuit (<NUM>) configured to measure a voltage of the bus-bar (<NUM>, <NUM>, <NUM>), a voltage of the battery pack (<NUM>, <NUM>), and voltages of the plurality of battery modules (<NUM>, <NUM>, <NUM>, <NUM>); and
a processor (<NUM>) configured to diagnose a connection status of the bus-bar (<NUM>, <NUM>, <NUM>) and a connection status of the wire (<NUM>, <NUM>) based on a current of the battery pack (<NUM>, <NUM>), the voltage of the bus-bar (<NUM>, <NUM>, <NUM>), the voltage of the battery pack (<NUM>, <NUM>), and the voltages of the plurality of battery modules (<NUM>, <NUM>, <NUM>, <NUM>).