JP2019053829A - Battery pack - Google Patents

Abstract

To provide a battery pack capable of efficiently rising temperature of a battery cell.SOLUTION: A battery pack includes: a group cell 10 including a plurality of battery cells 11-15; a wiring board 20 disposed oppositely to the group cell; and bus bars 60-64 electrically connecting the wiring board and on-vehicle equipment. A connection site 60a with the wiring board in the bus bars is located in a region 20c facing the group cell on the wiring board.SELECTED DRAWING: Figure 2

Description

  The disclosure described in the present specification relates to a battery pack having a plurality of battery cells.

  As shown in Patent Document 1, a battery unit including an assembled battery module having a plurality of single cells and a control board that controls charging / discharging of the assembled battery module is known. Each of the plurality of single cells is a lithium ion storage battery.

  The assembled battery module and the control board are arranged opposite to each other so that the assembled battery module is at the bottom and the control board is at the top. The control board has an overlapping part that overlaps the assembled battery module vertically and a non-overlapping part that does not overlap vertically with the assembled battery module.

  A through hole is formed in a non-overlapping portion of the control board. The bus bar of the terminal block is inserted into this through hole. The terminal block is electrically connected to a lead storage battery or a generator outside the battery unit.

Japanese Patent No. 5926645

  As described above, the battery pack disclosed in Patent Document 1 employs a lithium ion storage battery as a single battery (battery cell). Such a secondary battery has a property of high resistance when the temperature is low. Therefore, for example, when the temperature of the battery cell is low because the external environment temperature is low, it is difficult to obtain high output from the assembled battery module.

  Therefore, an object of the present disclosure is to provide a battery pack capable of efficiently raising the temperature of battery cells.

One of the disclosures is a battery module (10) having a plurality of battery cells (11-15);
A wiring board (20) disposed opposite to the battery module;
A bus bar (60 to 64) for electrically connecting the wiring board and the in-vehicle device (110, 120, 130, 150),
The battery module has a battery stack (10i, 10j) in which a plurality of battery cells are arranged in the height direction,
The wiring board and the battery module are lined up in the height direction,
The connection part (60a) with the wiring board in a bus bar is located in the opposing area | region (20c) with the battery module in a wiring board.

  According to this, the heat generated due to the contact resistance at the connection part (60a) can be efficiently generated compared with the configuration in which the connection part of the bus bar with the wiring board is in the non-facing region of the wiring board with the battery module. It can give to a cell (11-15). Thereby, the temperature of the battery cells (11 to 15) can be increased efficiently, and the resistance of the battery cells (11 to 15) can be lowered. As a result, the output of the battery module (10) can be increased.

  In addition, the code | symbol with the parenthesis is attached | subjected to the element as described in the claim as described in a claim, and each means for solving a subject. The reference numerals in parentheses are for simply indicating the correspondence with each component described in the embodiment, and do not necessarily indicate the element itself described in the embodiment. The description of the reference numerals with parentheses does not unnecessarily narrow the scope of the claims.

It is a block diagram for demonstrating a power supply system. It is a schematic diagram for demonstrating schematically the structure of a battery pack. It is a chart for demonstrating switch control. It is a chart for demonstrating the electric current at the time of switch control. It is a chart for demonstrating the electric current at the time of switch control. It is a chart for demonstrating the shape of a 4th bus bar. It is a chart for demonstrating arrangement | positioning in the battery pack of a 4th bus bar. It is a chart for demonstrating the connection form of a bus-bar and a wiring board. It is a top view for demonstrating the position of a bus-bar and a wiring board.

  Hereinafter, embodiments will be described with reference to the drawings.

(First embodiment)
A battery pack 100 according to the present embodiment and a power supply system 200 including the battery pack 100 will be described with reference to FIGS.

<Overview of power supply system>
The power supply system 200 is mounted on a vehicle. The power supply system 200 includes a plurality of in-vehicle devices mounted on a vehicle and the battery pack 100. One of in-vehicle devices is a lead storage battery 110. The battery pack 100 has an assembled battery 10. The power supply system 200 constructs a two-power supply system by using the lead storage battery 110 and the assembled battery 10.

  An engine 140 is another on-vehicle device. A vehicle equipped with power supply system 200 has an idle stop function of stopping engine 140 when a predetermined stop condition is satisfied and restarting engine 140 when a predetermined start condition is satisfied.

  As shown in FIG. 1, the power supply system 200 includes a starter motor 120, a rotating electrical machine 130, an electric load 150, a host ECU 160, and an MGECU 170 in addition to the lead storage battery 110 and the engine 140 described above. Each of the lead storage battery 110, the starter motor 120, and the electric load 150 is electrically connected to the battery pack 100 via the first wire harness 201. The rotating electrical machine 130 is electrically connected to the battery pack 100 via the second wire harness 202.

  The host ECU 160 and the MGECU 170 are electrically connected to the lead storage battery 110 and the battery pack 100 via wiring (not shown). Similarly, other various ECUs mounted on the vehicle are also electrically connected to the lead storage battery 110 and the battery pack 100 through wiring (not shown).

  As described above, the power supply system 200 constructs a dual power supply system that uses two of the lead storage battery 110 and the battery pack 100 (the assembled battery 10) as power supplies.

  The lead storage battery 110 generates an electromotive voltage by a chemical reaction. The lead storage battery 110 has a larger storage capacity than the assembled battery 10. The lead storage battery 110 corresponds to an in-vehicle power source.

  Starter motor 120 starts engine 140. The starter motor 120 is mechanically coupled to the engine 140 when the engine 140 is started. The crankshaft of the engine 140 is rotated by the rotation of the starter motor 120. When the rotational speed of the crankshaft of engine 140 exceeds a predetermined rotational speed, mist-like fuel is injected from the fuel injection valve into the combustion chamber. At this time, a spark is generated by the spark plug. As a result, the fuel explodes and the engine 140 starts to rotate autonomously. The driving force of the vehicle is obtained by the power of the engine 140. When engine 140 starts to rotate autonomously, mechanical connection between starter motor 120 and engine 140 is released.

  The rotating electrical machine 130 performs power running and power generation. The rotating electrical machine 130 is connected to an inverter (not shown). This inverter is electrically connected to the second wire harness 202.

  The inverter converts a DC voltage supplied from at least one of the lead storage battery 110 and the assembled battery 10 of the battery pack 100 into an AC voltage. This AC voltage is supplied to the rotating electrical machine 130. Thereby, the rotating electrical machine 130 is powered.

  The rotating electrical machine 130 is connected to the engine 140. The rotating electrical machine 130 and the engine 140 can transmit rotational energy to each other via a belt or the like. The rotational energy generated by the power running of the rotating electrical machine 130 is transmitted to the engine 140. Thereby, the rotation of the engine 140 is promoted. As a result, vehicle travel is assisted. As described above, a vehicle equipped with the power supply system 200 has an idle stop function. The rotating electrical machine 130 not only assists the vehicle travel, but also functions to rotate the crankshaft when the engine 140 is restarted.

  The rotating electrical machine 130 also has a function of generating electric power by at least one of the rotational energy of the engine 140 and the rotational energy of the wheels of the vehicle. The rotating electrical machine 130 generates an alternating voltage by power generation. This AC voltage is converted into a DC voltage by an inverter. This DC voltage is supplied to each of the battery pack 100, the lead storage battery 110, and the electric load 150.

  The engine 140 generates driving force of the vehicle by driving the fuel to burn. As described above, when the engine 140 is started, the crankshaft is rotated by the starter motor 120. However, when the engine 140 is stopped once by the idle stop and then restarted, the crankshaft is rotated by the rotating electrical machine 130 when the predetermined starting condition is satisfied.

  The electric load 150 includes a general load 151 and a protective load 152. The general load 151 includes in-vehicle devices such as a seat heater, a blower fan, an electric compressor, a room light, and a headlight that may not have a constant supply power. The protective load 152 includes an in-vehicle device such as an electric shift position, an electric power steering (EPS), a brake (ABS), a door lock, a navigation system, and an in-vehicle device that is required to have a constant supply power. The protective load 152 illustrated here has a property of switching from the on state to the off state when the supply voltage falls below the reset threshold. The protective load 152 includes in-vehicle devices that are more relevant to vehicle travel than the general load 151.

  The host ECU 160 and the MGECU 170 are one of various ECUs mounted on the vehicle. These various ECUs are electrically connected to each other via a bus wiring 161 to construct an in-vehicle network. Various ECUs perform coordinated control to control combustion of the engine 140, power generation and power running of the rotating electrical machine 130, and the like. The host ECU 160 controls the battery pack 100, and the MGECU 170 controls the rotating electrical machine 130.

  Although not shown, the power supply system 200 includes sensors for measuring physical information such as various voltages and currents, and vehicle information such as accelerator pedal depression amount and throttle valve opening, in addition to the above-described in-vehicle devices. Have. Detection signals detected by these various sensors are input to various ECUs.

<Outline of battery pack>
Next, the battery pack 100 will be described. As shown in FIG. 1, the battery pack 100 has external connection terminals indicated by double circles. The external connection terminals include a first external connection terminal 100a, a second external connection terminal 100b, a third external connection terminal 100c, and a fourth external connection terminal 100d.

  The first external connection terminal 100 a and the fourth external connection terminal 100 d are electrically connected to the lead storage battery 110, the starter motor 120, and the electric load 150 via the first wire harness 201. The second external connection terminal 100 b is electrically connected to the rotating electrical machine 130 via the second wire harness 202. The third external connection terminal 100c is bolted to the vehicle body. The bolt inserted into the third external connection terminal 100c functions to connect the battery pack 100 and the vehicle body. Thereby, the battery pack 100 is body-grounded.

  As shown in FIG. 1, the first wire harness 201 is divided into a lead battery 110, a starter motor 120, and a general load 151, and a protective load 152. The first wire harness 201 connecting the lead storage battery 110, the starter motor 120, and the general load 151 is connected to the first external connection terminal 100a. The first wire harness 201 that connects the protective load 152 is connected to the fourth external connection terminal 100d.

  As shown in FIG. 1, the battery pack 100 includes an assembled battery 10, a wiring board 20, a switch 30, a sensor unit 40, a BMU 50, and a bus bar 60. The battery pack 100 has a housing (not shown).

  A part of the switch 30 and the BMU 50 are mounted on the wiring board 20. The remaining switch 30 is mounted on the housing via an insulating film. The control electrode of the switch 30 mounted on the housing is electrically connected to the wiring board 20 via the first internal connection member. Thereby, an electric circuit is configured. The sensor unit 40 is electrically connected to this electric circuit.

  This electrical circuit is electrically connected to each of the first external connection terminal 100a, the second external connection terminal 100b, the assembled battery 10, and the fourth external connection terminal 100d via the bus bar 60. Thus, the electric circuit of the battery pack 100 is electrically connected to the lead storage battery 110, the starter motor 120, the rotating electrical machine 130, the assembled battery 10, and the electric load 150. The electric circuit is connected to the vehicle body via a bolt inserted into the third external connection terminal 100c.

  The casing of the battery pack 100 is generated by aluminum die casting. The housing has a bottom and an annular side wall extending from the bottom. The assembled battery 10, the wiring board 20, the switch 30, the sensor unit 40, the BMU 50, and the bus bar 60 are housed in the housing space of the casing formed by the bottom and side walls. The housing also functions to radiate heat generated in the assembled battery 10 and the wiring board 20. The casing may be manufactured by pressing iron or stainless steel.

  A hole is formed in the bottom of the housing. This hole corresponds to the third external connection terminal 100c. And the opening part is comprised by the side wall of the housing | casing. This opening is covered with a resin or metal cover. Thereby, the electric circuit and the assembled battery 10 are waterproofed.

  The housing (battery pack 100) of this embodiment is provided below the seat of the vehicle. However, the arrangement of the housing is not limited to this. The housing can be arranged in, for example, a space between the rear seat and the trunk room and a space between the driver seat and the passenger seat.

<Battery pack components>
The assembled battery 10 is smaller than the lead storage battery 110 and is lighter in weight. The assembled battery 10 has a property of higher energy density than the lead storage battery 110.

  The assembled battery 10 has a plurality of battery cells connected in series. The battery cell is a lithium ion battery. A lithium ion battery generates an electromotive voltage by a chemical reaction. A current flows through the battery cell by generating the electromotive voltage. Thereby, the battery cell generates heat. The battery cell expands. The battery cell is not limited to the above example. For example, a secondary battery such as a nickel hydride secondary battery or an organic radical battery can be used as the battery cell.

  The wiring board 20 is a printed board on which a wiring pattern made of a conductive material is formed on at least one of the surface and the inside of the insulating board. As this wiring pattern, there are a first load supply wiring 21 and a second load supply wiring 22.

  Terminals that are electrically connected to the wiring pattern are formed on the wiring board 20. These terminals include a first internal terminal 23a, a second internal terminal 23b, and a third internal terminal 23c. The electrical connection between the wiring pattern and the internal terminals will be described later when the circuit configuration of the battery pack 100 is described later.

  The switch 30 includes a first switch 31, a second switch 32, a third switch 33, and a fourth switch 34. The first switch 31 and the second switch 32 are mounted on the housing. The third switch 33 and the fourth switch 34 are mounted on the wiring board 20.

  Each of the first switch 31 to the fourth switch 34 includes a semiconductor switch. This semiconductor switch is specifically an N-channel MOSFET.

  Each of the first switch 31 to the fourth switch 34 has at least one open / close section in which two MOSFETs are connected in series. The source electrodes of the two MOSFETs are connected to each other. The gate electrodes of the two MOSFETs are electrically independent. The MOSFET has a parasitic diode. The anode electrodes of the parasitic diodes of the two MOSFETs are connected to each other.

  The first switch 31 and the second switch 32 have a plurality of opening / closing sections. The plurality of opening / closing sections are connected in parallel. The source electrodes of the plurality of opening / closing parts are electrically connected to each other.

  The third switch 33 has one opening / closing part. The fourth switch 34 has a plurality of opening / closing sections. The plurality of open / close sections of the fourth switch 34 are connected in series.

  In FIG. 1, two open / close portions of the first switch 31 and the second switch 32 connected in parallel are shown. Two open / close sections connected in series with the fourth switch 34 are shown. The number of these open / close sections can be determined according to the amount of current, redundancy, and the like. However, the number of opening / closing parts is not particularly limited.

  As described above, the sensor unit 40 is electrically connected to the electric circuit. The sensor unit 40 includes sensor elements that detect the states of the assembled battery 10 and the switch 30. The sensor unit 40 includes a temperature sensor, a current sensor, and a voltage sensor as sensor elements.

  The sensor unit 40 detects the temperature, current, and voltage of the assembled battery 10. The sensor unit 40 outputs it to the BMU 50 as a status signal of the assembled battery 10. The sensor unit 40 detects the temperature, current, and voltage of the switch 30. The sensor unit 40 outputs it to the BMU 50 as a status signal of the switch 30.

  The sensor unit 40 includes a submergence sensor in addition to the temperature sensor, the current sensor, and the voltage sensor. This submergence sensor has a capacitor constituted by two counter electrodes. If there is water between the two counter electrodes, the dielectric constant (capacitance) of the capacitor changes. This capacitance is input to the BMU 50 as a status signal. The BMU 50 detects the submersion of the battery pack 100 based on whether or not the change in capacitance continues for a predetermined time.

  The BMU 50 controls the switch 30 based on at least one of the state signal of the sensor unit 40 and the command signal from the host ECU 160. BMU is an abbreviation for battery management unit. The BMU 50 corresponds to a control unit.

  The BMU 50 determines the state of charge (SOC) of the assembled battery 10 and the abnormality of the switch 30 based on the state signal of the sensor unit 40. SOC is an abbreviation for state of charge. The BMU 50 outputs a signal (determination information) that determines these SOC and abnormality to the host ECU 160.

  The host ECU 160 determines control of the switch 30 based on the determination information input from the BMU 50 and the vehicle information input from other various ECUs. The host ECU 160 then outputs a command signal including the determined control of the switch 30 to the BMU 50.

  The BMU 50 controls the switch 30 based on a command signal from the host ECU 160. This switch control will be described in detail later. If the BMU 50 determines that the battery pack 100 has been submerged based on the state signal of the submersion sensor, the BMU 50 autonomously stops the output of the control signal to the switch 30.

  The bus bar 60 is made of a conductive material such as copper. The bus bar 60 can be manufactured by, for example, the methods listed below. The bus bar 60 can be manufactured by bending one flat plate. The bus bar 60 can be manufactured by integrally connecting a plurality of flat plates. The bus bar 60 can be manufactured by welding a plurality of flat plates. The bus bar 60 can be manufactured by pouring a molten conductive material into a mold. The bus bar 60 can also be manufactured by the other manufacturing methods listed above. A method for manufacturing the bus bar 60 is not particularly limited.

  The battery pack 100 includes a first bus bar 61, a second bus bar 62, a third bus bar 63, and a fourth bus bar 64 as the bus bar 60. The electric circuit and the assembled battery 10, and the electric circuit and the external connection terminal are electrically connected by the plurality of bus bars. In FIG. 1, each of these bus bars 60 is shown thicker than the load supply wiring of the wiring board 20.

<Battery pack circuit configuration>
Hereinafter, the circuit configuration of the battery pack 100 will be described with reference to FIG. The first external connection terminal 100 a and one end of the first switch 31 are electrically connected via the first bus bar 61. A part of the first bus bar 61 is branched from a portion connecting the first external connection terminal 100 a and one end of the first switch 31. The branch portion 61 a of the first bus bar 61 is brazed to the first internal terminal 23 a of the wiring board 20.

  The other end of the first switch 31 and the second external connection terminal 100 b are electrically connected via the second bus bar 62. A part of the second bus bar 62 branches off from a portion connecting the other end of the first switch 31 and the second external connection terminal 100b. A branch portion 62 a of the second bus bar 62 is connected to one end of the second switch 32.

  The other end of the second switch 32 and the positive electrode of the assembled battery 10 are electrically connected via the third bus bar 63. A part of the third bus bar 63 branches off from a portion connecting the other end of the second switch 32 and the assembled battery 10. The branch portion 63 a of the third bus bar 63 is brazed to the second internal terminal 23 b of the wiring board 20. The negative electrode of the assembled battery 10 is electrically connected to the third external connection terminal 100c via the second internal connection member.

  The first internal terminal 23 a and the second internal terminal 23 b of the wiring board 20 are electrically connected via the first load supply wiring 21. A third switch 33 and a fourth switch 34 are connected in series to the first load supply wiring 21 in order from the first internal terminal 23a to the second internal terminal 23b.

  A portion of the first load supply wiring 21 between the third switch 33 and the fourth switch 34 and the third internal terminal 23 c are electrically connected via the second load supply wiring 22. The third internal terminal 23 c is electrically connected to the fourth external connection terminal 100 d through the fourth bus bar 64. The third internal terminal 23c and the fourth bus bar 64 are brazed.

  With the above electrical connection configuration, the first switch 31, the second switch 32, the fourth switch 34, and the third switch 33 are sequentially connected in a ring shape. A midpoint between the first switch 31 and the second switch 32 is connected to the second external connection terminal 100b. A midpoint between the second switch 32 and the fourth switch 34 is connected to the assembled battery 10. A midpoint between the fourth switch 34 and the third switch 33 is connected to the fourth external connection terminal 100d. A midpoint between the third switch 33 and the first switch 31 is connected to the first external connection terminal 100a.

  With the above electrical connection configuration, the electrical connection between the first external connection terminal 100a and the second external connection terminal 100b is controlled by controlling the opening and closing of the first switch 31. In other words, the electrical connection between the lead storage battery 110 and the rotating electrical machine 130 is controlled by opening / closing the first switch 31.

  By controlling the opening and closing of the second switch 32, the electrical connection between the second external connection terminal 100b and the assembled battery 10 is controlled. In other words, the electrical connection between the rotating electrical machine 130 and the assembled battery 10 is controlled by controlling the opening and closing of the second switch 32.

  By controlling the opening and closing of the fourth switch 34, the electrical connection between the second internal terminal 23b and the third internal terminal 23c is controlled. In other words, the electrical connection between the battery pack 10 and the protective load 152 is controlled by opening / closing the fourth switch 34.

  By controlling the opening and closing of the third switch 33, the electrical connection between the first internal terminal 23a and the third internal terminal 23c is controlled. In other words, the electrical connection between the lead storage battery 110 and the protective load 152 is controlled by controlling the opening and closing of the third switch 33.

  The first bus bar 61 corresponds to a power bus bar. The second bus bar 62 and the third bus bar 63 correspond to the electric bus bar. The fourth bus bar 64 corresponds to a load bus bar. The second switch 32 corresponds to an electrical switch. The third switch 33 corresponds to a load switch.

<Switch control>
Next, typical switch control of the battery pack 100 will be described with reference to FIGS. In FIG. 3, the closed state is indicated as ON, and the open state is indicated as OFF. In FIGS. 4 and 5, the current is indicated by broken-line arrows, and the reference numerals are omitted to avoid complication.

  Note that the switch control is appropriately changed according to the SOC of the lead storage battery 110 and the assembled battery 10, the vehicle requirements, and the like. Therefore, the switch control shown in FIGS. 3 to 5 is merely an example, and the present invention is not limited to this.

  As shown in FIG. 3, the switch control includes (a) Pb start control, (b) idle stop control, (c) Li restart control, (d) Pb restart control, (e) Li travel control, (f There are first) power generation control and (g) second power generation control.

  (A) Pb start control is switch control when the starter motor 120 starts the vehicle. The BMU 50 executes this switch control when the ignition switch is turned on from off. The BMU 50 closes the third switch 33 and opens the other three switches. As a result, as shown in the column (a) of FIG. 4, the lead storage battery 110 and the protective load 152 are electrically connected via the third switch 33. Power is supplied from the lead storage battery 110 to the starter motor 120 and the general load 151, and power is supplied from the lead storage battery 110 to the protective load 152 via the third switch 33. The engine 140 is cranked by driving the starter motor 120. Although not shown, in this Pb start control, the BMU 50 may perform control to close the first switch 31 and the third switch 33 and open the other two switches.

  At the time of starting such a vehicle, for example, the temperature of the battery cell of the assembled battery 10 may be low because the external environment temperature is low. Thus, when the temperature of a battery cell is low, since the resistance is high, there exists a possibility that sufficient electric power cannot be supplied from the assembled battery 10. FIG. For example, if electric power is supplied from the assembled battery 10 to the protective load 152 in a state where the output of the assembled battery 10 is not sufficient, the supply voltage to the protective load 152 may fall below the reset threshold value, thereby causing the protective load 152 to be turned off. For this reason, the output of the assembled battery 10 is not made when the engine 140 is started.

  (B) The idle stop control is switch control when the engine 140 is stopped when a predetermined stop condition is satisfied. The BMU 50 closes the first switch 31 and the fourth switch 34 and opens the other two switches. As a result, as shown in the column (b) of FIG. 4, the assembled battery 10 and the protective load 152 are electrically connected via the fourth switch 34. Since the rotating electrical machine 130 is not driven, no current flows, but the lead storage battery 110 and the rotating electrical machine 130 are electrically connected via the first switch 31. Power is supplied from the lead storage battery 110 to the general load 151, and power is supplied from the assembled battery 10 to the protective load 152 via the fourth switch 34. This idle stop control is the same as the switch control when the rotating electrical machine 130 is not driven and the vehicle travels using only the engine 140 as a drive source.

  (C) Li restart control is switch control when the engine 140 is restarted when the SOC of the battery pack 10 is high and a predetermined start condition is satisfied. The BMU 50 closes the second switch 32 and the fourth switch 34 and opens the other two switches. As a result, as shown in the column (c) of FIG. 4, the assembled battery 10 and the rotating electrical machine 130 are electrically connected via the second switch 32. The assembled battery 10 and the protective load 152 are electrically connected via the fourth switch 34. Power is supplied from the assembled battery 10 to the rotating electrical machine 130 via the second switch 32, and power is supplied from the assembled battery 10 to the protective load 152 via the fourth switch 34. Further, electric power is supplied from the lead storage battery 110 to the general load 151. This Li restart control is the same as the switch control when the vehicle travels using both the engine 140 and the rotating electrical machine 130 as drive sources.

  (D) Pb restart control is switch control when the engine 140 is restarted when the SOC of the battery pack 10 is low and a predetermined start condition is satisfied. The BMU 50 closes the first switch 31 and the fourth switch 34 and opens the other two switches. As a result, the lead storage battery 110 and the rotating electrical machine 130 are electrically connected via the first switch 31 as shown in the column (d) of FIG. The assembled battery 10 and the protective load 152 are electrically connected via the fourth switch 34. Power is supplied from the lead storage battery 110 to the general load 151, and power is supplied from the lead storage battery 110 to the rotating electrical machine 130 via the first switch 31. Further, power is supplied from the assembled battery 10 to the protective load 152 via the fourth switch 34.

  (E) Li travel control is switch control when the vehicle travels using only the rotating electrical machine 130 as a drive source. The BMU 50 closes the second switch 32 and the third switch 33 and opens the other two switches. As a result, as shown in the column (e) of FIG. 4, the assembled battery 10 and the rotating electrical machine 130 are electrically connected via the second switch 32. The lead storage battery 110 and the protective load 152 are electrically connected via the third switch 33. Power is supplied from the assembled battery 10 to the rotating electrical machine 130 via the second switch 32. In addition, power is supplied from the lead storage battery 110 to the general load 151, and power is supplied from the lead storage battery 110 to the protective load 152 via the third switch 33.

  (F) The first power generation control is switch control when the rotating electrical machine 130 is in a power generation state and the SOC of the assembled battery 10 is low. The BMU 50 closes the first switch 31, the second switch 32, and the fourth switch 34, and opens the third switch 33. As a result, as shown in the column (f) of FIG. 4, the lead storage battery 110 and the rotating electrical machine 130 are electrically connected via the first switch 31. The assembled battery 10 and the rotating electrical machine 130 are electrically connected via the second switch 32. The protective load 152 and the rotating electrical machine 130 are electrically connected via the second switch 32 and the fourth switch 34. Thereby, the generated power generated in the rotating electrical machine 130 is supplied to the lead storage battery 110 via the first switch 31. The generated power is supplied to the assembled battery 10 via the second switch 32. The generated power is supplied to the protective load 152 via the second switch 32 and the fourth switch 34.

  (G) The second power generation control is switch control when the rotating electrical machine 130 is in the power generation state and the SOC of the assembled battery 10 is high. The BMU 50 closes the first switch 31 and the third switch 33 and opens the other two switches. As a result, as shown in the column (g) of FIG. 4, the lead storage battery 110 and the rotating electrical machine 130 are electrically connected via the first switch 31. The protective load 152 and the rotating electrical machine 130 are electrically connected via the first switch 31 and the third switch 33. Thereby, the generated power generated in the rotating electrical machine 130 is supplied to the lead storage battery 110 via the first switch 31. The generated power is supplied to the protective load 152 via the first switch 31 and the third switch 33.

  Although not shown, the battery pack 100 has a bypass circuit. This bypass circuit has a normally closed relay together with a supply wiring connecting the lead storage battery 110 and the protective load 152. The BMU 50 stops outputting the control signal to the switch 30 when parked or stopped. Accordingly, the first switch 31 to the fourth switch 34 are opened. At this time, the BMU 50 also stops supplying the control signal to the relay. As a result, the relay is closed, and the lead storage battery 110 and the protective load 152 are electrically connected. Therefore, when the vehicle is parked or stopped, power is supplied from the lead storage battery 110 to the protective load 152 via the bypass circuit.

  As described above, some switch controls are premised on the output (discharge) from the assembled battery 10. Specifically, (b) idle stop control, (c) Li restart control, (d) Pb restart control, and (e) Li travel control is based on switch control based on the output from the battery pack 10. It has become. In such switch control on the assumption of the output from the assembled battery 10, at least one of the BMU 50 and the host ECU 160 determines that the temperature of the assembled battery 10 is sufficiently high and the SOC of the assembled battery 10 is sufficiently high. Done if you do.

  When the temperature of the assembled battery 10 is low, the second switch 32 and the fourth switch 34 are fixed in the open state. Switch control is limited to opening and closing of the first switch 31 and the second switch 32. Further, idle stop and power running of the rotating electrical machine 130 are also prohibited. However, the above (f) first power generation control is performed regardless of the temperature of the assembled battery 10 because it supplies power to the assembled battery 10. In this case, the second switch 32 and the fourth switch 34 are controlled to be closed.

  Note that at least one of the BMU 50 and the host ECU 160 stores a threshold for determining the temperature of the assembled battery 10 and the level of the SOC. At least one of the BMU 50 and the host ECU 160 determines the temperature of the battery pack 10 and the level of the SOC based on this threshold value and the status signal of the sensor unit 40.

<Battery pack structure>
Next, the structure of the battery pack 100 will be described. In the following, the three directions that are orthogonal to each other are referred to as a horizontal direction, a vertical direction, and a height direction. Further, the bottom side of the casing in the height direction is indicated as the lower side, and the cover side covering the opening of the casing is indicated as the upper side. In the present embodiment, the vertical direction is along the advancing / retreating direction of the vehicle. The lateral direction is along the left-right direction of the vehicle. The height direction is along the vertical direction of the vehicle.

  FIG. 2 shows the assembled battery 10, the wiring board 20, a part of the switch 30, and the bus bar 60 as components of the battery pack 100. The assembled battery 10 includes a first battery cell 11 to a fifth battery cell 15 as battery cells. The first battery cell 11 to the fifth battery cell 15 are accommodated in a case 16.

  The battery cell has a quadrangular prism shape. For this purpose, the battery cell has six sides. The battery cell has a first main surface 10a and a second main surface 10b facing in the height direction. The battery cell has a first side surface 10c and a second side surface 10d facing in the lateral direction. The battery cell has an upper end surface 10e facing in the vertical direction. Although not shown, the battery cell has a lower end surface facing in the vertical direction. Of these six surfaces, the first main surface 10a and the second main surface 10b are larger in area than the other surfaces. The battery cell has a flat shape with a thin length (thickness) between the first main surface 10a and the second main surface 10b.

  A positive electrode terminal 10g and a negative electrode terminal 10h as electrode terminals 10f are formed on the upper end surface 10e of the battery cell. In FIG. 2, the positive electrode terminal 10g and the negative electrode terminal 10h are indicated by broken lines. The positive electrode terminal 10g and the negative electrode terminal 10h are arranged apart from each other in the horizontal direction. The positive terminal 10g is located on the first side surface 10c side. The negative electrode terminal 10h is located on the second side surface 10d side.

  As shown in FIG. 2, in the height direction, the first battery cell 11, the fourth battery cell 14, and the fifth battery cell 15 are arranged in order from the lower side to the upper side to form the first battery stack 10i. It is configured. The second main surfaces 10b of the first battery cell 11 and the fourth battery cell 14 face each other in the height direction. The first main surfaces 10a of the fourth battery cell 14 and the fifth battery cell 15 face each other in the height direction. Thereby, the positive electrode terminals 10g and the negative electrode terminals 10h are alternately arranged in the height direction.

  Similarly, the second battery cell 12 and the third battery cell 13 are arranged side by side in order from the lower side to the upper side in the height direction to constitute the second battery stack 10j. The 2nd main surface 10b of each of the 2nd battery cell 12 and the 3rd battery cell 13 has mutually opposed in the height direction. Thereby, the positive electrode terminals 10g and the negative electrode terminals 10h are alternately arranged in the height direction.

  The first battery stack 10i and the second battery stack 10j are arranged in the horizontal direction. The positive terminal 10g of the first battery cell 11 and the negative terminal 10h of the second battery cell 12 are arranged in the horizontal direction. The negative electrode terminal 10h of the fourth battery cell 14 and the positive electrode terminal 10g of the third battery cell 13 are arranged in the horizontal direction.

  In the arrangement of the five battery cells described above, the positive electrode terminal 10g of the first battery cell 11 and the negative electrode terminal 10h of the second battery cell 12 are electrically connected via a series terminal 17 extending in the lateral direction. The positive terminal 10g of the second battery cell 12 and the negative terminal 10h of the third battery cell 13 are electrically connected via a series terminal 17 extending in the height direction. The positive terminal 10g of the third battery cell 13 and the negative terminal 10h of the fourth battery cell 14 are electrically connected via a series terminal 17 extending in the lateral direction. The positive terminal 10g of the fourth battery cell 14 and the negative terminal 10h of the fifth battery cell 15 are electrically connected via a series terminal 17 extending in the height direction. Thereby, the five battery cells are electrically connected in series.

  An output terminal 18 is connected to each of the negative terminal 10 h of the first battery cell 11 and the positive terminal 10 g of the fifth battery cell 15. The output terminal 18 connected to the negative electrode terminal 10 h of the first battery cell 11 corresponds to the negative electrode of the assembled battery 10. The output terminal 18 connected to the positive electrode terminal 10 g of the fifth battery cell 15 corresponds to the positive electrode of the assembled battery 10.

  Strictly speaking, the case 16 includes a first case that houses battery cells, and a second case in which the series terminal 17 and the output terminal 18 are provided. These two cases are mechanically connected to each other so that the battery cell is housed in the case 16 and the corresponding electrode terminal 10f of the battery cell, the series terminal 17 and the output terminal 18 are in contact with each other. In this contact state, the corresponding electrode terminal 10f, the series terminal 17 and the output terminal 18 are welded by a laser or the like. Thereby, the assembled battery 10 is configured. The assembled battery 10 corresponds to a battery module.

  The case 16 has a first stack storage space 16f corresponding to the first battery stack 10i and a second stack storage space 16g corresponding to the second battery stack 10j. The first stack storage space 16f and the second stack storage space 16g are arranged in the horizontal direction.

  As shown in FIG. 2, the first stack storage space 16f is divided into three storage spaces in order to individually store the three battery cells. The second stack storage space 16g is partitioned into two storage spaces in order to store the two battery cells individually. Therefore, the lengths of the first stack storage space 16f and the second stack storage space 16g in the height direction are different. A first upper end surface 16i located on the uppermost side of the outer wall surface 16h of the case 16 constituting the first stack storage space 16f and a first uppermost surface 16h located on the outermost wall surface 16h of the case 16 constituting the second stack storage space 16g. The position in the height direction is different from the upper end surface 2j.

  The first stack storage space 16f includes a first storage space 16a, a fourth storage space 16d, and a fifth storage space 16e arranged in order from the lower side to the upper side in the height direction. The second stack storage space 16g has a second storage space 16b and a third storage space 16c arranged in order from the lower side to the upper side in the height direction.

  The first storage space 16a and the second storage space 16b are arranged in the horizontal direction. The third storage space 16c and the fourth storage space 16d are arranged in the horizontal direction. With the above storage space arrangement, an empty space 10k corresponding to one storage space is formed above the fourth storage space 16d. In FIG. 2, the empty space 10k is surrounded by a dashed line. The empty space 10k is located between the first upper end surface 16i and the second upper end surface 16j in the height direction. The empty space 10k is aligned with the fifth storage space 16e in the lateral direction. At least a part of the wiring board 20 is provided in the empty space 10k. A projection area in the height direction of the second upper end surface 16j of the wiring board 20 corresponds to the facing area 20c.

  The wiring board 20 has a front surface 20a and a back surface 20b facing in the height direction. The wiring board 20 has a flat shape with a thin length (thickness) between the front surface 20a and the back surface 20b. The wiring board 20 is disposed to face the assembled battery 10 in the height direction. The back surface 20b of the wiring board 20 faces the second upper end surface 16j of the case 16 in the height direction. A part of the switch 30 is mounted in a region 20 c facing the case 16 in the height direction of the wiring board 20. More specifically, at least a part of the third switch 33 and the fourth switch 34 are mounted on the surface 20a of the facing region 20c of the wiring board 20. In the present embodiment, the third switch 33 is mounted in the facing area 20c. In FIG. 2, the opposing region 20c is shown surrounded by a broken line.

  The length (thickness) in the height direction of the wiring board 20 is shorter than the length in the height direction of one storage space for storing one battery cell of the case 16. For this reason, the wiring board 20 is provided in the empty space 10k, but there is an extra space for providing members other than the wiring board 20 in the empty space 10k. As will be described later, a part of the bus bar 60 is provided in this extra space.

  A through hole 24 for connecting to the bus bar 60 is formed in the wiring board 20. The through hole 24 penetrates the front surface 20a and the back surface 20b. One end of the bus bar 60 is inserted into the through hole 24. One end of the bus bar 60 inserted into the through hole 24 is electrically connected to the wiring board 20 by the solder 25. The through hole 24 corresponds to the above internal terminal.

  The through hole 24 is formed in the facing region 20 c of the wiring board 20. Therefore, the connection portion of the wiring board 20 with the bus bar 60 faces the case 16 in the height direction. In other words, the connection part 60a of the bus bar 60 with the wiring board 20 faces the case 16 in the height direction.

  In the present embodiment, the through hole 24 not only faces the case 16 in the height direction, but is also arranged in the height direction with the third battery cell 13 positioned in the middle of the five battery cells electrically connected in series. Yes. Further, in the present embodiment, the through hole 24 is formed in a portion spaced apart from the first battery stack 10 i to the second battery stack 10 j side in the lateral direction of the wiring board 20. In other words, if an adjacent space 101 described later is used, the through hole 24 is formed on the adjacent space 101 side in the lateral direction of the wiring board 20.

  As described above, the bus bar 60 includes the first bus bar 61, the second bus bar 62, the third bus bar 63, and the fourth bus bar 64. Of these four bus bars, the first bus bar 61, the third bus bar 63, and the fourth bus bar 64 are connected to the wiring board 20. Therefore, one end of the first bus bar 61, the third bus bar 63, and the fourth bus bar 64 is inserted into the through hole 24. Each of the first bus bar 61, the third bus bar 63, and the fourth bus bar 64 has a connection portion 60a. The connection part 60a faces the assembled battery 10 in the height direction.

  2, 6, and 7, only the fourth bus bar 64 is shown as a representative of the three bus bars connected to the wiring board 20. Hereinafter, although the shape, arrangement, connection, and the like of the fourth bus bar 64 will be described, this can also be appropriately adopted in the first bus bar 61 and the third bus bar 63.

  As shown in FIGS. 2, 6, and 7, the fourth bus bar 64 has a curved shape after the flat plate is formed into a predetermined shape. The fourth bus bar 64 has an external connection portion 65 connected to the wire harness, an internal connection portion 66 connected to the through hole 24, and a connection portion 67 that connects the external connection portion 65 and the internal connection portion 66. The boundary between the external connection portion 65 and the connection portion 67 and the boundary between the connection portion 67 and the internal connection portion 66 are bent.

  The external connection portion 65 is thin in the height direction and has a flat shape extending in the lateral direction. The external connection portion 65 is formed with a through hole 65a penetrating in the height direction for mechanically and electrically connecting the first wire harness 201 with a bolt or the like. The external connection portion 65 corresponds to the fourth external connection terminal 100d.

  The external connection portion 65 is located in the adjacent space 10l aligned with the second battery stack 10j in the lateral direction. In FIG. 2, the adjacent space 101 is surrounded by a two-dot chain line. In the lateral direction, the adjacent space 101, the second stack storage space 16g, and the first stack storage space 16f are arranged in this order. Therefore, in the lateral direction, the external connection portion 65, the second stack storage space 16g, and the first stack storage space 16f are arranged in order. A connecting portion 67 is integrally connected to an end portion of the external connecting portion 65 on the second stack storage space 16g side.

  The internal connection portion 66 has a flat shape extending in the height direction with a small thickness in the lateral direction. At least a part of the internal connection part 66 is located in the empty space 10k. More specifically, at least a part of the internal connection portion 66 is located between the wiring board 20 and the case 16 in the empty space 10k.

  The tip 66a of the internal connection portion 66 is branched into a plurality and protrudes in the height direction in order to be inserted into the through hole 24 of the wiring board 20. The tip 66a of the internal connection portion 66 is inserted into the through hole 24 from the back surface 20b to the front surface 20a. The part inserted into the through hole 24 of the tip 66a corresponds to a connection part 60a with the wiring board 20 in the fourth bus bar 64. A connecting portion 67 is integrally connected to the end of the internal connecting portion 66 on the second stack storage space 16g side.

  The connecting portion 67 has a shape that extends smoothly and continuously from the connecting end portion with the external connecting portion 65 toward the connecting end portion of the internal connecting portion 66. In other words, the connecting portion 67 has a shape that is smoothly curved and extended from the adjacent space 101 to the empty space 10k. The connecting portion 67 faces the second stack storage space 16g, but has a flat shape with a thin length (thickness) in the facing direction.

  The connecting portion 67 includes a first connecting portion 67a extending along the height direction from the connecting end portion with the external connecting portion 65 toward the empty space 10k, and a connecting end of the internal connecting portion 66 from the first connecting portion 67a. And a second connecting portion 67b extending in an arc shape toward the portion. As shown in FIGS. 6 and 7, the first connecting portion 67a has a longer length (width) in the vertical direction than the second connecting portion 67b. The first connecting portion 67a has the same length (width) in the vertical direction as the external connecting portion 65. The second connecting portion 67b has the same length (width) in the vertical direction as the internal connecting portion 66. In FIG. 7C, the wiring board 20 is shown in a semi-transparent manner in order to clarify the arrangement of each component. Therefore, the shape of the case 16 positioned below the wiring board 20 is clearly indicated by a solid line.

  The second connecting portion 67b has a shorter separation distance from the second stack storage space 16g than the first connecting portion 67a. The second connecting portion 67b is curved in an arc shape so as to protrude in a direction away from the second stack storage space 16g. The curvature of the second connecting portion 67b is determined so that the insulation between the connecting portion 67 and the second battery stack 10j is maintained and the length of the second connecting portion 67b is the shortest.

(Function and effect)
As described above, the through hole 24 is formed in the region 20 c of the wiring board 20 facing the case 16. A bus bar 60 is connected to the through hole 24. Therefore, the connection part 60a with the wiring board 20 in the bus bar 60 faces the case 16 in the height direction.

  According to this, the heat generated due to the contact resistance at the connection portion 60a can be efficiently applied to the assembled battery 10 as compared with the configuration in which the connection portion with the bus bar is located in the non-opposing region of the wiring board with the case. Can do. Thereby, a battery cell can be heated up efficiently and the resistance of a battery cell can be lowered. As a result, the output of the assembled battery 10 can be increased.

  As described above, for example, when the temperature of the battery cell of the assembled battery 10 is low because the external environment temperature is low, the switch control based on the output of the assembled battery 10 is not performed. Speaking of the switch control shown in FIG. 3, (b) idle stop control, (c) Li restart control, (d) Pb restart control, and (e) Li travel control on the premise of the output of the assembled battery 10 Is not done. The switch control is limited to (a) Pb start control, (f) first power generation control, and (g) second power generation control.

  On the other hand, in the present embodiment, the connection portion 60 a of the fourth bus bar 64 with the wiring board 20 faces the case 16. As shown in FIGS. 4 and 5, the fourth bus bar 64 has (a) Pb start control, (f) first power generation control, and (g) second power generation control not premised on the output of the assembled battery 10. Current flows in each.

  According to this, the heat generated at the connection portion 60 a of the fourth bus bar 64 can be applied to the assembled battery 10 when the engine 140 is started by the starter motor 120. Thereby, the temperature of the assembled battery 10 can be raised efficiently when the vehicle is started. Therefore, it is possible to release the switch control restriction soon after the engine 140 is started. In addition, heat generated at the connection portion 60 a of the fourth bus bar 64 during power generation by the rotating electrical machine 130 can be efficiently applied to the assembled battery 10.

  Note that, the current flows through the first bus bar 61 in the same manner as the fourth bus bar 64 in (a) Pb start control, (f) first power generation control, and (g) second power generation control. Therefore, heat generated at the connection portion 60a of the first bus bar 61 with the wiring board 20 at the time of starting the engine 140 by the starter motor 120 and at the time of power generation by the rotating electrical machine 130 can be efficiently applied to the assembled battery 10. This also makes it possible to release the restriction on the switch control soon after the vehicle is started. Further, the heat generated at the connection portion 60 a of the first bus bar 61 during power generation by the rotating electrical machine 130 can be efficiently applied to the assembled battery 10.

  A current flows through the third bus bar 63 in (f) first power generation control. Therefore, when the generated power is supplied from the rotating electrical machine 130 to the assembled battery 10, the heat generated at the connection portion 60 a of the third bus bar 63 can be efficiently applied to the assembled battery 10.

  At least a part of the wiring board 20 is provided in the empty space 10k that is above the fourth storage space 16d of the second stack storage space 16g and is arranged in the lateral direction with the fifth storage space 16e of the first stack storage space 16f. . According to this, the increase in the physique of the battery pack 100 is suppressed.

  A third switch 33 is mounted on the facing region 20 c of the wiring board 20. As described above, a current flows through the third switch 33 in (a) Pb start control. Therefore, the heat generated by the third switch 33 when the engine 140 is started by the starter motor 120 can be efficiently applied to the assembled battery 10.

  The third battery cell 13 located in the middle of the five battery cells electrically connected in series is easy to transfer the temperature to the other four battery cells due to electrical connection and convenience of arrangement.

  On the other hand, in the present embodiment, the through hole 24 of the wiring board 20 is aligned with the third battery cell 13 in the height direction. For this reason, the connection part 60a of the bus bar 60 is aligned with the third battery cell 13 in the height direction. Thereby, the heat generated at the connection part 60 a of the bus bar 60 can be transferred to the other four battery cells via the third battery cell 13. As a result, the temperature of the assembled battery 10 can be increased efficiently.

  The through hole 24 is formed on the adjacent space 10 l side where the external connection portion 65 of the fourth bus bar 64 is provided in the lateral direction of the wiring board 20. Thereby, the increase in the size of the fourth bus bar 64 is suppressed.

  The internal connection portion 66 of the fourth bus bar 64 is located in the empty space 10k. Thereby, the increase in the physique of the battery pack 100 is suppressed.

  The boundary between the external connection portion 65 and the connection portion 67 and the boundary between the connection portion 67 and the internal connection portion 66 are bent. And the connection part 67 has comprised the shape which curved and extended smoothly toward the connection end part of the internal connection part 66 from the connection end part with the external connection part 65. As shown in FIG. This suppresses the vibration of the external connection portion 65 from being transmitted to the internal connection portion 66. In other words, the vibration of the internal connection portion 66 is suppressed from being transmitted to the external connection portion 65. Thereby, it is suppressed that the electrical connection failure in the external connection part 65 arises. Further, it is possible to suppress electrical connection failure in the internal connection portion 66.

  The second connecting portion 67b is curved in an arc shape so as to protrude in a direction away from the second stack storage space 16g, and the bending maintains the insulation between the connecting portion 67 and the second battery stack 10j, and the second The length of the connecting portion 67b is determined to be the shortest. Thereby, the increase in the physique of the battery pack 100 is suppressed.

  The preferred embodiments of the present disclosure have been described above. However, the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present disclosure. It is.

(First modification)
In this embodiment, the 2nd connection part 67b showed the example curved in the arc shape so that it might become convex in the direction away from the 2nd stack storage space 16g. However, the shape of the second connecting portion 67b is not limited to the above example. For example, as shown in the column (a) of FIG. 8, the second connecting portion 67b may have a linear shape extending in the lateral direction.

  In the present embodiment, the fourth bus bar 64 is inserted into the through hole 24 of the wiring board 20 and connected by the solder 25. However, the connection form between the fourth bus bar 64 and the wiring board 20 is not limited to the above example. For example, as shown in the columns (b) and (c) of FIG. 8, the fourth bus bar 64 and the wiring board 20 may be connected by screws 26 and nuts 27.

  In this case, the connecting portion 67 of the fourth bus bar 64 extends to the upper side of the surface 20 a of the wiring substrate 20, and the internal connection portion 66 extends in the lateral direction toward the wiring substrate 20. A hole penetrating in the height direction is formed in the internal connection portion 66. A nut 27 having a thread groove formed inside is fixed to the through hole 24 by solder or the like. In a state where the holes of the nut 27 and the holes of the internal connection portion 66 are arranged in the height direction, the screws 26 are passed through these holes, and the screws 26 are fastened to the nut 27. Also by this, the 4th bus bar 64 and the wiring board 20 can be connected.

  In the present embodiment, an example in which at least a part of the fourth bus bar 64 is located in the empty space 10k is shown. However, for example, as shown in each of the columns (b) and (c) of FIG. 8, the fourth bus bar 64 may not be located in the empty space 10k.

  Further, as the shape of the fourth bus bar 64, as shown in the column (c) of FIG.

  Furthermore, as shown in the column (d) of FIG. 8, the fourth bus bar 64 may be formed by connecting a plurality of conductive members by separate connecting members 28 such as screws.

  Of course, the shape of the fourth bus bar 64 shown in each of the columns (a) to (d) of FIG. 8 and the connection to the wiring board 20 are also applied to the first bus bar 61 and the third bus bar 63, respectively. Is possible.

(Second modification)
In the present embodiment, an example in which the fourth bus bar 64 is connected to the facing region 20c in the height direction of the wiring board 20 with the assembled battery 10 is shown. However, as the connection position between the wiring board 20 and the fourth bus bar 64, for example, the configuration shown in FIG. 9 can be adopted. In FIG. 9, a region surrounded by a one-dot chain line is a region surrounded by the four lines shown below. Two of the four wires are components along the longitudinal direction of the tangent line of each portion of the assembled battery 10 that protrudes most in the two directions of one side and the other side of the assembled battery 10 in the lateral direction. The remaining two lines are components along the lateral direction of the tangent line of each part of the assembled battery 10 that protrudes most in the two directions of the longitudinal direction on one side and the other side with respect to the assembled battery 10. An assembled battery region 10m indicating a substantial arrangement region of the assembled battery 10 is formed by connecting these four lines. The fourth bus bar 64 may be connected to the facing region 20c of the wiring board 20 in the height direction with respect to the assembled battery region 10m.

(Third Modification)
In this embodiment, the assembled battery 10 showed the example which has five battery cells. However, the assembled battery 10 should just have a some battery cell, and is not limited to the said example. Also, the number of battery stacks may be one or three or more instead of two.

(Fourth modification)
In the present embodiment, an example in which a vehicle equipped with the power supply system 200 has an idle stop function is shown. However, the vehicle equipped with the power supply system 200 is not limited to the above example. For example, a hybrid vehicle or an electric vehicle can be employed. In this case, the starter motor 120 and the rotating electrical machine 130 shown in the present embodiment replace the motor generator.

DESCRIPTION OF SYMBOLS 10 ... Assembly battery, 10i ... 1st battery stack, 10j ... 2nd battery stack, 11 ... 1st battery cell, 12 ... 2nd battery cell, 13 ... 3rd battery cell, 14 ... 4th battery cell, 15 ... 1st 5 battery cells, 16 ... case, 16i ... first upper end surface, 16j ... second upper end surface, 20 ... wiring board, 20c ... opposite area, 30 ... switch, 31 ... first switch, 32 ... second switch, 33 ... 3rd switch, 34 ... 4th switch, 50 ... BMU, 60 ... bus bar, 60a ... connection part, 61 ... 1st bus bar, 62 ... 2nd bus bar, 63 ... 3rd bus bar, 64 ... 4th bus bar, 665 ... outside Connection part, 66 ... internal connection part, 67 ... connection part, 100 ... battery pack, 110 ... lead-acid battery, 120 ... starter motor, 130 ... rotating electric machine, 140 ... engine, 150 ... electric load, 151 ... general load, 1 2 ... protection load, 200 ... power supply system

Claims (5)

A battery module (10) having a plurality of battery cells (11-15);
A wiring board (20) disposed opposite to the battery module;
A bus bar (60 to 64) for electrically connecting the wiring board and the in-vehicle device (110, 120, 130, 150);
The battery module has a battery stack (10i, 10j) in which a plurality of the battery cells are arranged in the height direction,
The wiring board and the battery module are arranged in the height direction,
The connection part (60a) with the said wiring board in the said bus bar is a battery pack located in the opposing area | region (20c) with the said battery module in the said wiring board. Examples of the in-vehicle devices include an in-vehicle power source (110), a starter motor (120), an electric load (150), and an engine (140).
As the bus bar, there are a load bus bar (64) for electrically connecting the wiring board and the electric load, and a power bus bar (61) for electrically connecting the wiring board and the in-vehicle power source,
A load switch (33) for controlling connection between the load bus bar and the power bus bar;
A control unit (50) for controlling the opening and closing of the load switch,
When the engine is driven by the starter motor, the control unit controls the load switch to be closed so that a current flows through the load bus bar and the power bus bar,
2. The battery pack according to claim 1, wherein at least one of a connection part of the load bus bar with the wiring board and a connection part of the power bus bar with the wiring board is located in the facing region of the wiring board. As the in-vehicle device, there is a rotating electrical machine (130),
As the bus bar, there is an electric bus bar (62, 63) for electrically connecting the wiring board and the rotating electric machine,
An electric switch (32) for controlling connection between the rotating electric machine and the battery module;
A control unit (50) for controlling opening and closing of the electric switch,
The controller is configured to pass a current through the electric bus bar by controlling the electric switch to a closed state during power generation of the rotating electric machine,
3. The battery pack according to claim 1, wherein a connection portion of the electric bus bar with the wiring board is in the facing region of the wiring board. The battery module has a plurality of the battery stacks,
A plurality of the battery stacks are arranged in a lateral direction intersecting the height direction,
The positions of the upper end surfaces (16i, 16j) in the height direction of the plurality of battery stacks are different in the height direction,
The battery pack according to any one of claims 1 to 3, wherein at least a part of the wiring board is positioned between the upper end surfaces of the plurality of battery stacks in the height direction. The bus bar includes an external connection part (65) connected to the in-vehicle device, an internal connection part (66) connected to the wiring board, and a connection part (67) connecting the external connection part and the internal connection part. )
5. The battery pack according to claim 1, wherein at least one of a boundary between the external connection portion and the connection portion and a boundary between the connection portion and the internal connection portion is bent.

Images