GB2608955A

GB2608955A - Straddled vehicle battery pack and straddled vehicle

Info

Publication number: GB2608955A
Application number: GB2215467.8A
Authority: GB
Inventors: Hino Haruyoshi
Original assignee: Yamaha Motor Co Ltd
Current assignee: Yamaha Motor Co Ltd
Priority date: 2020-04-22
Filing date: 2021-04-20
Publication date: 2023-01-18
Also published as: GB2608955A8; GB202215467D0

Abstract

An objective of the present invention is to provide a straddled vehicle battery pack (1) that can be charged in a short time with a simple and compact configuration. Provided are a plurality of lithium-ion batteries (11), a case (12), and an electrical connector (13) which is connected to a paired connector and which is attached to the case which transmits a current inputted and outputted with respect to a vehicle body (102). The straddled vehicle battery pack has a charge capacity of 2.5 Ah or greater, a maximum charge voltage from 12 V to 60 V inclusive, and includes a plate-like busbar (14) by which the electrical connector and the plurality of lithium-ion batteries are connected in series rather than parallel, such that electric power converted into motive power for increasing the driving force of a straddled vehicle (100) is received and outputted. The plate-like busbar has a width (W) and a thickness (T) such that the electric power for increasing the driving force of the straddled vehicle is charged by a current flowing through a pathway formed by the series connection under the maximum charge voltage of 12 V to 60 V inclusive.

Description

DESCRIPTION

Title of Invention

STRADDLED VEHICLE BATTERY PACK AND STRADDLED VEHICLE

Technical Field

[0001] The present teaching relates to a straddled vehicle-battery pack, and a straddled vehicle.

Background Art

[0002] A battery pack for use in a straddled vehicle is disclosed for example, in Patent Literature 1 (PTL D. The straddled vehicle of PTL 1 is a vehicle having no engine. PTL 1 illustrates an electric motorcycle as an example of the straddled vehicle. The battery pack of PTL 1 is installed in a straddled vehicle.

C\I The battery pack of PTL 1 includes plural casings for accommodating C\I battery units. A heat dissipation space is formed between some of the plural r casings. This is how the technique of PTL 1 attempts to increase the heat dissipation ability of the battery pack while the battery pack retains a great 20 amount of energy capacity

O

Citation List Patent Literature [0003] PTL 1: Japanese Patent Application Laid-Open No. 2013-232280

Summary of Invention

Technical Problem [0004] It is desired that a straddled vehicle-battery pack for use in a straddled vehicle be downsized with a simple configuration, for the purpose of improving mountability to the vehicle. It is also desired that a straddled vehicle-battery pack for use in a straddled vehicle be capable of being charged with electricity within a short amount of time, the electricity being adequate to increase a driving force of the straddled vehicle.

[0005] The present teaching aims to provide a straddled vehicle-battery pack 35 capable of being downsized with a simple configuration, and capable of being charged with electricity within a short amount of time, the electricity being adequate to increase a driving force of a straddled vehicle.

Solution to the Problem [0006] The present inventor examined characteristics of a straddled vehicle-battery pack suitable for a straddled vehicle.

[0007] A straddled vehicle is configured such that the vehicle posture is controlled by a rider's weight-shifting when traveling.

A battery module for an EV forklift is disclosed for example, in Japanese Patent Application Laid-Open No. 2014-180185. The forklift is a vehicle primarily intended to lift and carry heavy objects. The forklift is not configured such that the vehicle posture is controlled by a rider's weight-shifting. The forklift is weighted such that a weight balance can be kept when carrying a heavy object.

As for the straddled vehicle, on the other hand, there tends to be desire for downsizing, from the viewpoint of the maneuverability and travel performance mentioned above. The weight ratio of a straddled vehicle-battery pack to the entire straddled vehicle is higher than those of the other components mounted. A straddled vehicle-battery pack for use in a straddled vehicle is required to be small in size while being capable of receiving and outputting electricity for increasing a driving force.

[0008] As a result of studies on a straddled vehicle-battery pack having such characteristics, the present inventor discovered the followings.

[0009] Normally in a battery pack, plural batteries are used in combination, 25 for the purpose of providing a great amount of energy capacity or charge capacity.

For example, the battery pack of PTL 1 includes plural batteries. For example, in PTL 1, 168 batteries for instance are connected in parallel and in series, to provide an increased amount of energy capacity. In more detail, 12 batteries that are connected in parallel form one group, and 14 groups are connected in series. The battery pack of PTL 1 includes a control section. The control section is a battery management controller (BMC) having a CPU and a memory. The control section monitors and controls charge states of the batteries connected in parallel. The control section is connected, by electric :35 wire, to each of the batteries included in the battery pack. The control section monitors a state of each battery. The control section centralizes the controlling of each battery. In other words, information from each battery representing a state of the battery is centralized at the control section. Based on the centralized information, the control section controls each battery. More specifically the control section, which is connected to each battery and has the CPU and the memory, detects the temperature, the electric current, the voltage, the frequency of use, and the like, of each battery, and thus centralizes and monitors the state of each battery, and also controls each battery [00101 In the battery pack of PTL 1, 12 batteries that form one group are connected in parallel. The batteries connected in parallel show variations in their characteristics including an internal resistance, due to the state of an electrode and the state of an electrolyte. When charging, equal voltages are applied to the batteries connected in parallel. However, electric currents flowing through the batteries connected in parallel depend on the variations in characteristics. To be precise, therefore, charging amounts of the batteries connected in parallel differ depending on the variations in characteristics. The control section controls, by detecting the state of each battery the charging amount of a battery that is likely to have a different charging amount because of the parallel connection.

[00111 The present inventor examined various configurations of a straddled vehicle-battery pack suitable for a straddled vehicle. In the examination by the present inventor, a straddled vehicle-battery pack having a charge capacity of 2.5 Ah or more was configured by setting a charging voltage of the straddled vehicle-battery pack to 12 V or more and 60 V or less while purposely connecting plural lithium ion batteries in series instead of in parallel with one another. Additionally in the examination, a plate-shaped bus bar was used for the series connection of the plural lithium ion batteries, the plate-shaped bus bar having a length, a width, and a thickness, the thickness being smaller than both the length and the width. The present inventor discovered that this configuration allows the straddled vehicle-battery pack to be downsized with a simple configuration so that it can be charged within a short amount of time. Since the charging voltage of the straddled vehicle-battery pack having a charge capacity of 2.5 Ah or more is set to 12 V or more, the straddled vehicle-battery pack is capable of charging electricity adequate to increase the driving force of the straddled vehicle.

:15 [00121 When plural lithium ion batteries are not connected in parallel but connected in series with one another, electric currents flowing through the respective lithium ion batteries at a time of charging are substantially equal. That is, the electric currents flowing through the respective lithium ion batteries are substantially equal irrespective of an internal resistance of each lithium battery. It therefore is easy to keep a balance between charging amounts of the respective lithium ion batteries. Accordingly, for example, a circuit that manages an electric current, a voltage, or a temperature of each lithium ion battery can be simplified or eliminated. For example, it is possible to keep a balance between charging amounts of the respective lithium ion batteries, without a control device for monitoring and controlling states of lithium ion batteries connected in parallel. Consequently, a straddled vehicle-battery pack having a simple configuration and being small in size can be achieved.

[00131 In the configuration, the plural lithium ion batteries are not connected in parallel but connected in series with one another, while the maximum voltage that the straddled vehicle-battery pack can charge is 20 V or more and 60 V or less. In this case, the maximum voltage applied across the plural lithium ion batteries connected in series is 60 V or less.

Thus, the straddled vehicle-battery pack operates in a range that belongs to "extra low voltage (ELV)" or "safety extra low voltage (SELV)" according to the IEC (International Electrotechnical Commission) standard No. IEC60950. Since the voltage of the straddled vehicle-battery pack is a low voltage, its insulation structure can be simpler than that of a high-voltage one. [00141 As mentioned above, the voltage applied across the plural lithium ion batteries connected in series is a low voltage belonging to the "extra low voltage". In this case, the number of lithium ion batteries connected in series can be reduced as compared to a case of, for example, belonging to a voltage range higher than a voltage belonging to the "extra low voltage". As a result, variations in charging ability characteristics between the respective lithium ion batteries included in the straddled vehicle-battery pack can be reduced as compared to a case of, for example, using many lithium ion batteries for adaptation to high voltages. This allows further simplification or elimination of the monitoring and controlling circuit. Accordingly, a straddled vehicle-battery pack having a simple configuration and being small in size can be achieved.

[00151 The plural lithium ion batteries are connected in series by bus bars, respectively An electrical connector is attached to a casing. The electrical connector can also be connected by a bus bar. The bus bar has a plate-like shape having a length, a width, and a thickness. The thickness is smaller than both the length and the width.

For example, the battery module shown in Japanese Patent Application Laid-Open No. 2014-180185 mentioned above is a module for a business use forklift The battery module of the forklift is charged during non-business hours, for example. In the battery module of the forklift, a short charge time is not expected for charging a large electric current, and neither is a bus bar shown, nor is the structure of a bus bar shown.

Connecting the plural lithium ion batteries in series by the plate-shaped bus bars without any parallel connection can simplify the shapes and arrangement of the bus bars so that an arrangement region of the bus bars can be reduced, as compared to a case of combining parallel connection and series connection of plural lithium ion batteries, for example. Accordingly, a straddled vehicle-battery pack can he achieved without a control device for monitoring and controlling the states of lithium ion batteries connected in parallel.

The bus bar has an electrical resistance lower than that of a wire having a conductor diameter equal to the thickness of the bus bar and having a length equal to the length of the bus bar, for example. Thus, when a charging electric current of the lithium ion batteries connected in series flows through the bus bars, a further suppressed amount of heat is generated by the bus bars themselves. In addition, when a discharging electric current of the lithium ion batteries connected in series flows through the bus bars, an amount of heat generated by the bus bars themselves is further suppressed. Accordingly, in the straddled vehicle-battery pack, a structure for heat dissipation, which is required in charging with a large electric current, can be simplified and downsized. Consequently, charging with a large electric current can be enabled without parallel connection of the plural lithium ion batteries. This an makes it possible for, for example, an electric motor vehicle equipped with the straddled vehicle-battery pack to be charged in a time length near a time length required for replenishment of a liquid fuel at a conventional or existing gas station. A long-time occupation of a charge station is therefore not necessary. [00161 In this manner, eliminating parallel connection while allowing a supply :35 of a charging electric current from the outside in accordance with specifications of the straddled vehicle-battery pack makes it possible to keep a balance between charging amounts of the respective lithium ion batteries, without a control device for monitoring and controlling lithium batteries connected in parallel. It is also possible to simplify the insulation structure. It is possible to achieve a straddled vehicle-battery pack having a simple configuration and being small in size. It is possible to charge the straddled vehicle-battery pack within a short amount of time, because charging the straddled vehicle-battery pack with a large electric current can be enabled without parallel connection of the plural lithium ion batteries.

Accordingly, a straddled vehicle-battery pack having a simple 10 configuration, being small in size, and being capable of charging electricity within a short amount of time can be achieved, the electricity being adequate to increase a driving force of a straddled vehicle.

[00171 A straddled vehicle-battery pack according to aspects of the present teaching, which is accomplished based on the above-described knowledge, has 15 the following configurations.

[00181 (1) A straddled vehicle-battery pack for use in a straddled vehicle, the straddled vehicle-battery pack comprising: plural lithium ion batteries; a casing that accommodates the plural lithium ion batteries; and an electrical connector attached to the casing, the electrical connector being connected to a mating connector that is disposed in a vehicle body of the straddled vehicle, the electrical connector being configured to transmit electric current received from and outputted to the vehicle body, the straddled vehicle-battery pack having a charge capacity of 2.5 Ah or more, a maximum charging voltage of 12 V or more and 60 V or less, and a plate-shaped bus bar for connecting the electrical connector and the plural lithium ion batteries in series without any parallel connection, to be able to receive and output electricity that is to be converted into motive power for increasing a driving force of the straddled vehicle, the plate-shaped bus bar having such a width and a thickness that charging of electricity for increasing the driving force of the straddled vehicle can be made possible with an electric current flowing along a single route that is formed by the series connection under the maximum charging voltage of 12 V or more and 60 V or less.

[00191 In the foregoing configuration, the straddled vehicle-battery pack:15 includes the plural lithium ion batteries, the casing, the electrical connector, and the bus bar. The electrical connector is attached to the casing. The electrical connector is connected to the mating connector that is disposed in the vehicle body. The bus bar connects the connector and the plural lithium ion batteries in series without any parallel connection. The straddled vehicle-battery pack has a charge capacity of 2.5 Ah or more, and a maximum charging voltage of 12 V or more and 60 V or less. With this, the straddled vehicle-battery pack receives and outputs electricity that is to be converted into motive power for increasing the driving force of the straddled vehicle. The bus bar is plate-shaped. The bus bar has such a width and a thickness that charging of electricity for increasing the driving force of the straddled vehicle can be made possible with the electric current flowing along the single route that is formed by the series connection. The bus bar has such a width and a thickness that charging of the electricity can be made possible with an electric current flowing along the single route, under the maximum charging voltage of 12 V or more and 60 V or less.

The bus bar has an electrical resistance lower than that of a wire having a conductor diameter equal to the thickness of the bus bar and having a length equal to the length of the bus bar, for example. Thus, when an electric current flows in the single route formed by the series connection of the lithium ion batteries and the electrical connector, a further suppressed amount of heat is generated by the bus bar itself. Accordingly, a structure for heat dissipation, which is required in charging with a large electric current, can be simplified and downsized.

With the bus bar connecting the plural lithium ion batteries in series without any parallel connection, the straddled vehicle-battery pack has a charge capacity of 2.5 Ah or more. The straddled vehicle-battery pack has a maximum charging voltage of 12 V or more and 60 V or less, as a voltage corresponding to a voltage across the series connection. Here, 12 V is the lower limit of a voltage widely used as a voltage of a power source that contributes to increasing a driving force of a straddled vehicle. The charge capacity of 2.5 Ah or more corresponds to electricity capable of increasing a driving force of a straddled vehicle, unlike a capacity for operating a low-power device such as a mobile phone. The straddled vehicle-battery pack having a charge capacity of 2.5 Ah or more and a maximum charging voltage of 12 V or more and 60 V or less is capable of receiving and outputting electricity with which the driving force of the straddled vehicle can be increased.

Since the bus bar connects the plural lithium ion batteries in series without any parallel connection, arrangement of the bus bar can be simplified as compared to when, for example, parallel connection and series connection coexist. In a case of plural lithium ion batteries connected in parallel for example, electric currents flowing through the respective lithium ion batteries connected in parallel at a time of charging vary depending on internal resistances of the respective lithium ion batteries. As a result, the lithium ion batteries have different charging amounts.

In a structure of plural lithium ion batteries connected in series without any parallel connection, electric currents flowing through the respective lithium ion batteries at a time of charging are substantially equal. It therefore is easy to keep a balance between charging amounts of the respective lithium ion batteries. Accordingly, for example, a circuit for monitoring a charging amount of each lithium ion battery can be simplified or eliminated.

With the bus bar having the above-described structure connecting the plural lithium ion batteries in series without any parallel connection, downsizing of the straddled vehicle-battery pack can be achieved while electricity adapted to increase the driving force of the straddled vehicle can be charged within a short amount of time.

[0020] The plural lithium ion batteries are not connected in parallel but connected in series with one another by the bus bar. In a case of plural lithium ion batteries connected in parallel for example, the lithium ion batteries connected in parallel receive electric currents when connected to a power source for charging, the electric currents being different depending on internal resistances of the respective lithium ion batteries. As a result, the lithium ion batteries have different charging amounts.

In a structure of plural lithium ion batteries connected in series without any parallel connection, electric currents that are being received by the respective lithium ion batteries at a time of charging are substantially equal.

It therefore is easy to keep a balance between charging amounts of the respective lithium ion batteries. Accordingly, the straddled vehicle-battery pack can be achieved without any control device for monitoring and controlling the states of lithium ion batteries connected in parallel.

Furthermore, the bus bar connects the connector and the plural lithium 35 ion batteries in series without any parallel connection. This can simplify the shape of each bus bar as well as a mutual arrangement of bus bars, as compared to a case of combining a parallel connection and a series connection of plural lithium ion batteries, for example. Accordingly, the size of arrangement space of the bus bar can be reduced.

[0021] In the configuration, the plural lithium ion batteries are not connected in parallel but connected in series with one another, while the maximum voltage that the straddled vehicle-battery pack can charge is 20 V or more and 60 V or less. In this case, the maximum voltage applied across the plural lithium ion batteries connected in series is 60 V or less.

Thus, the straddled vehicle-battery pack operates in a range that is referred to as "extra low voltage" (extra-low voltage: ELV, or safety extra-low voltage: SELV) according to the IEC (International Electrotechnical Commission) standard No. IEC60950. Since the voltage of the straddled vehicle-battery pack is a low voltage, its insulation structure can be simpler than that of a high-voltage one. Accordingly, the straddled vehicle-battery pack can he downsized.

[0022] As mentioned above, the voltage applied across the plural lithium ion batteries connected in series is a low voltage referred to as "extra-low voltage". In this case, the number of lithium ion batteries connected in series can be reduced as compared to a case of, for example, being in a voltage range higher than a voltage being referred to as "extra-low voltage". As a result, variations in charging ability characteristics between the respective lithium ion batteries included in the straddled vehicle-battery pack can be reduced as compared to a case of, for example, using many lithium ion batteries for adaptation to high voltages. This allows further simplification or elimination of a circuit for monitoring the charging amount of each lithium ion battery, for example. Accordingly, the straddled vehicle-battery pack having a simple configuration and being small in size can be achieved.

[0023] As described above, the straddled vehicle-battery pack, in which a series connection is linked with a bus bar without any parallel connection, has a maximum charging voltage of 60 V or less and a charge capacity of 2.5 Ah or more. With this, electricity corresponding to the driving force of the straddled vehicle can be charged. Since the plural lithium ion batteries are connected in series by a bus bar without any parallel connection, the bus bar having such a width and a thickness that charging is achievable with an electric current :35 flowing along the above-described single route under the maximum charging voltage of 60 V or less, a wiring structure can be simplified. Moreover, both of a structure for dissipating heat involved in charging with a large electric current, as well as an insulation structure, can be simplified. The straddled vehicle-battery pack having a simple configuration and being small in size can be achieved. Because charging the straddled vehicle-battery pack with a large electric current can be achieved without parallel connection of the plural lithium ion batteries, the straddled vehicle-battery pack can be charged within a short amount of time.

Accordingly, the straddled vehicle-battery pack having a simple configuration and being small in size, and capable of charging electricity within 10 a short amount of time can be achieved, the electricity being adequate to increase the driving force of the straddled vehicle.

[00241 In an aspect of the present teaching, the straddled vehicle-battery pack may have the following configuration.

[00251 (2) In the straddled vehicle-battery pack according to (1), each of the plural lithium ion batteries has an independent negative electrode, the independent negative electrode containing at least any one selected from the group consisting of a spinel structure lithium titanate, a niobium-titanium-containing composite oxide, and graphite, the bus bar connecting the independent negative electrode to a positive electrode or a negative electrode without electrically connecting the independent negative electrode to another independent negative electrode, to provide a series-connection structure of the plural lithium ion batteries without any parallel connection.

[00261 In the foregoing configuration, each of the plural lithium ion batteries has the independent negative electrode. The structure having no parallel connection makes each negative electrode stand electrically independent from any other negative electrode. That is, each negative electrode is not electrically connected to any other independent negative electrode. Each of these negative electrodes contains at least any one selected from the group consisting of a spinel structure lithium titanate, a niobium-titanium-containing composite oxide, and graphite.

A negative electrode containing at least any one selected from the group consisting of a spinel structure lithium titanate, a niobium-titanium-containing composite oxide, and graphite can reduce the likelihood of occurrence of internal short-circuiting, which may otherwise be caused by deposition of lithium in a negative electrode as described in Japanese Patent Application Laid-Open No. 2015-153719, for example. Accordingly, a circuit for monitoring the charge state of each lithium ion battery can be simplified or eliminated. The bus bar connects such lithium ion batteries without electrically connecting an independent negative electrode to another independent negative electrode. This can simplify a structure of the bus bar as compared to a case of combining a parallel connection and a series connection, for example. Moreover, a circuit for monitoring and controlling each lithium ion battery can be further simplified or eliminated. For example, use of a conductor for detection, which is connected to each lithium ion battery to detect the charge state of the lithium ion battery, can be reduced or eliminated. Wiring, which includes the bus bar, can be further simplified. Accordingly, the straddled vehicle-battery pack capable of being downsized with a simpler configuration, and capable of charging within a short amount of time can be achieved.

[00271 In an aspect of the present teaching, the straddled vehicle-battery pack may have the following configuration.

(3) The straddled vehicle-battery pack according to (1) or (2) further includes an electric current breaker that breaks an electric current flowing 20 through the plural lithium ion batteries, the electric current breaker being connected in series with the electrical connector and the plural lithium ion batteries.

[00281 The foregoing configuration can suppress unintentional flow-out of the electric current of the plural lithium ion batteries to the outside through the electrical connector. It therefore is possible to suppress the following situation: in a case of detaching or attaching the straddled vehicle-battery pack from or to the vehicle body for example, the electrical connector is unintentionally in contact with a conductor at a location outside the straddled vehicle-battery pack, and as a result, a large electric current caused by short-circuiting welds the conductor become to the electrical connector. Accordingly, the likeliness that a situation whereby, for example, the external conductor becomes welded to the electrical connector can be suppressed with a simple configuration of the control device being simplified or eliminated.

[00291 In an aspect of the present teaching, the battery pack may have the 35 following configuration.

(4) In the straddled vehicle-battery pack according to any one of (1) to (3), a data output section is provided inside the casing, the data output section being configured to output specification data for identifying electrical 5 specifications of the straddled vehicle-battery pack, and the electrical connector includes a data communication terminal for outputting the specification data to the outside of the straddled vehicle-battery pack.

WM In the foregoing configuration, the specification data for identifying the electrical specifications of the straddled vehicle-battery pack is outputted from the data output section provided inside the casing to the outside of the straddled vehicle-battery pack via the electrical connector. This makes it possible for a charging electric current in accordance with the specifications of the straddled vehicle-battery pack to be supplied from the outside, for example.

Consequently, the lithium ion batteries can he charged with the charging electric current in accordance with the specifications, both when a control device for adjusting the amount of a charging electric current supplied from the outside is provided inside the straddled vehicle-battery pack and when the control device is not provided inside the straddled vehicle-battery pack.

[0031] In an aspect of the present teaching, the straddled vehicle-battery pack may have the following configuration.

(5) In the straddled vehicle-battery pack according to any one of (1) to (4), a charging-dedicated connector is attached to the casing, the charging-dedicated connector being configured to take a charging electric current directly into the straddled vehicle-battery pack from the outside of the straddled vehicle in which the straddled vehicle-battery pack is installed. [0032] The foregoing configuration makes it possible to take the charging electric current directly into the straddled vehicle-battery pack from the outside of the straddled vehicle, without changing a connection partner of the electrical connector.

[0033] In an aspect of the present teaching, the straddled vehicle may have the following configuration.

(6) A straddled vehicle includes: the straddled vehicle-battery pack according to any one of claims 1 to 5; a mating connector configured to be connected to the electrical connector of the straddled vehicle-battery pack; a driving wheel; a motor control device configured to control a supply of electricity from 5 the straddled vehicle-battery pack to a motor via the mating connector and a supply of electricity from the motor to the straddled vehicle-battery pack via the mating connector; and the motor configured to drive the driving wheel with electricity supplied from the motor control device as well as to generate electricity by the driving 10 wheel being driven, wherein the straddled vehicle is configured without inclusion of any control device that is configured to acquire at least one parameter from among an electric current, a voltage, or a temperature detected from each of the plural lithium ion batteries, and based on the at least one parameter acquired, to change a voltage and/or an electric current of at least one lithium ion battery of the plural lithium ion batteries.

[0034] With the foregoing configuration, the straddled vehicle having a simple configuration, being small in size and being capable of charging the battery pack within a short amount of time can be achieved.

[0035] In an aspect of the present teaching, the straddled vehicle may have the following configuration.

(7) The straddled vehicle according to (6) further includes: a handle bar for steering, disposed extending in a left-right direction of the straddled vehicle; and a saddle configured to have a rider sit straddling thereon, the straddled vehicle being configured, as a lean vehicle, to make a turn in such a manner that at a time of turning, a rider who grips the handle bar shifts their weight so as to make the straddled vehicle lean toward the inside of a curve.

[0036] For a straddled vehicle as a lean vehicle, the lightness and responsiveness in response to a rider's manipulation are important, and thus downsizing is highly desired. The straddled vehicle, however, is equipped with a straddled vehicle-battery pack, which makes achieving a high level of responsiveness and lightness not easy in a straddled vehicle as a lean vehicle.

:15 In this regard, the foregoing configuration can provide a straddled vehicle as a lean vehicle having good responsiveness and lightness, capable of being downsized with a simple configuration, and being capable of charging a battery pack within a short amount of time.

[00371 An increase in the driving force of the straddled vehicle can be made possible by using electricity stored in the straddled vehicle-battery pack. The term "electricity" as used herein encompasses at least chemical energy stored in a secondary battery pack, for example. In an exemplary configuration, the straddled vehicle may include a capacitor, too, and may travel not only with chemical energy but also with electrophysical energy stored in the capacitor. The straddled vehicle can be a vehicle having no engine, for example. The straddled vehicle can be a pure electric straddled vehicle, for example. The straddled vehicle, however, is not limited to the above, and may be a vehicle equipped with an engine as an internal combustion engine. For example, a plug-in hybrid vehicle having a function of charging with electricity supplied from the outside of the vehicle and capable of traveling also with an engine installed in the vehicle is encompassed by the straddled vehicle.

[00381 When the straddled vehicle travels, the straddled vehicle-battery pack is charged with electricity generated by the motor being driven by the driving wheel. The straddled vehicle-battery pack is connected to a charging apparatus disposed outside the straddled vehicle, to be charged. In a case where the straddled vehicle-battery pack is used in a straddled vehicle equipped with an engine, the straddled vehicle-battery pack is charged with electricity of a generator driven by the engine.

[00391 The straddled vehicle is a vehicle for riding in a riding style upon a saddle. A rider sits with legs astride a saddle of the straddled vehicle. The straddled vehicle is a lean vehicle, for example. Examples of the straddled vehicle include a scooter-type motorcycle, a moped-type motorcycle, an offroad-type motorcycle, and an on-road-type motorcycle. The straddled vehicle is not limited to a motorcycle, and may be an all-terrain vehicle (ATV) or the like, or may be a three-wheeled motorcycle, for example. The three-wheeled motorcycle may have two front wheels and one rear wheel, or may have one front wheel and two rear wheels.

[00401 The straddled vehicle-battery pack is a battery pack for use in a straddled vehicle. The straddled vehicle-battery pack is a pack having plural lithium ion batteries combined and integrated. The straddled vehicle-battery 85 pack is mounted to a vehicle body of the straddled vehicle.

The straddled vehicle-battery pack can be mounted to the vehicle body in a non-replaceable manner, for example.

[00411 The straddled vehicle-battery pack is not particularly limited, and for example, may be mounted to the vehicle body in a replaceable manner. The straddled vehicle-battery pack may be removable from the vehicle body without using a tool different from a key, such as a spanner, or may be replaceable in relation to the vehicle body by using a tool different from a key, such as a spanner.

[00421 The straddled vehicle-battery pack may not need to have a monitoring circuit for each lithium ion battery, for example. The monitoring circuit as used herein refers to a circuit that measures at least one parameter selected from a parameter group consisting of a voltage, an electric current, and a temperature, and outputs the at least one parameter to the outside. Examples of the monitoring circuit include a voltage detection circuit, an electric current detection circuit, and a temperature detection circuit. The straddled vehicle-battery pack may not need to have a voltage detection circuit for each lithium ion battery, for example. In such a case, the straddled vehicle-battery pack may have a monitoring circuit corresponding to another parameter (such as an electric current and/or a temperature) for each lithium ion battery, or may have a voltage detection circuit for the entire plurality of lithium ion batteries,

for example.

[00431 The lithium ion battery is a battery capable of charging and discharging. The lithium ion battery can be a secondary battery that performs charging and discharging through a chemical reaction on electrodes. The lithium ion battery performs charging and discharging through oxidation and reduction reactions on electrodes. The lithium ion battery converts chemical energy stored therein, into electrical energy. The lithium ion battery has its terminal voltage not in proportion to the amount of electricity stored in the battery. For example, a lithium ion capacitor is not encompassed by the lithium ion battery.

The lithium ion battery has a positive electrode containing a lithium oxide. A lithium battery having a positive electrode containing a lithium metal is not encompassed by the lithium ion battery. The lithium ion battery is a non-aqueous lithium ion battery using a non-aqueous electrolyte such as an organic solvent.

The lithium ion battery can be a battery capable of storing electricity for 85 driving the motor of the straddled vehicle. The lithium ion battery can be capable of storing electricity supplied from the outside of the straddled vehicle.

The lithium ion battery can be capable of storing electricity supplied from the motor in a case where the motor of the straddled vehicle generates electricity. In other words, the lithium ion battery can be capable of storing a regenerated electric current of the motor.

[00441 As the lithium ion battery, a lithium ion battery having a maximum continuous charge rate of 10 C or more can be used, for example. As the lithium ion battery, a lithium ion battery having a maximum continuous charge rate of 20 C or more can be used, for example. As the lithium ion battery, a lithium ion battery having a maximum continuous charge rate of 40 C or more can be used, for example. Here, it may be acceptable that the lithium ion battery has a maximum continuous charge rate of 10 C or less, for example.

The maximum charge rate refers to the highest maximum charge rate that can be provided to the lithium ion battery or the straddled vehicle-battery pack. The maximum charge rate represents the speed of charging. The unit is C. In a case of measurement of charging with a constant electric current, the magnitude of an electric current capable of completely charging the capacity of a battery in one hour is defined as 1 C. For example, 1 C is 2.5 A when the capacity of the battery is 2.5 Ah.

[00451 The capacity or charge capacity of a battery is the amount of electricity that can be charged in the battery,. The unit is Ah. The charge capacity is equal to the discharge capacity,. The discharge capacity is, for example, the amount of electric current accumulated over time, the electric current being outputted from when a full-charged battery starts outputting an electric current with outputting an initial voltage to when its output voltage reaches a final voltage. Discharge conditions are that the electric current must be discharged such that the final voltage is reached by ten-hours discharging, for example (ten hour rate). The straddled vehicle-battery pack is configured by series connection of lithium ion batteries. Therefore, a discharging voltage, which is a condition of the discharge capacity; varies depending on the number of lithium ion batteries included in the straddled vehicle-battery pack. The discharge capacity is set regardless of the number of lithium ion batteries.

The straddled vehicle-battery pack having a charge capacity of 2.5 Ah or more can charge or discharge electricity adequate to increase the driving force of the straddled vehicle. For example, in a case of a straddled vehicle-battery pack 1 having an output voltage of 12 V and a charge capacity of 2.5 Ah, outputting an electric current of 50 A for 20 seconds corresponds to an electricity consumption of about 10%. As a result of this consumption, the driving force can be assisted by about 600 W, or simply about 0.8 ps, for 20 seconds. The charge capacity of 2.5 Ah or more is at such a capacity level that by using 50% of the charge capacity, an increase of the driving force for 20 5 seconds can be continuously made five times at least without need of recharge. The straddled vehicle-battery pack having a charge capacity of 2.5 Ah or more, for example, is smaller in size than a device for charging electrophysical energy such as a capacitor.

[0046] The electrical connector transmits electric current received from and outputted to components of the vehicle body. For example, the electrical connector transmits an electric current that is outputted toward the motor of the straddled vehicle. For example, the electrical connector transmits an electric current that is supplied from the motor in a case where the motor of the straddled vehicle generates electricity.

The electrical connector can be used as a connector for transmitting an electric current that is supplied from the outside of the straddled vehicle. Alternatively, the electrical connector may be provided as a connector different from the connector for transmitting an electric current that is supplied from the outside of the straddled vehicle.

[0047] The electrical connector is attached to the casing. The electrical connector is not disposed at a position distant from the casing. For example, a connector disposed at the distal end of a flexible cable extending outward from the casing is different from the electrical connector of the present teaching. The electrical connector is attached so as to be fit into an opening formed in the casing, for example. The electrical connector, by being attached to the casing, is configured such that the positional relationship of the electrical connector relative to the casing cannot be changed, for example. The electrical connector may be attached to the vehicle body (for example, to a vehicle body covering) as well as to the casing, for example. The vehicle body covering may have an openable/closable lid at a position corresponding to the electrical connector attached to the casing, to make the electrical connector accessible from the outside when the lid is opened.

[0048] The bus bar is a member for transmitting an electric current. The bus bar is made of a metal. The bus bar is made of a copper or aluminium 35 material, for example. The bus bar is coupled to the lithium ion battery or the electrical connector. All of the wiring that connects the lithium ion batteries and the electrical connector in series is constituted by the bus bat The wiring is an electrical component primarily intended to transmit an electric current. In a route of the series connection, for example, electrical components may be disposed such as a fuse intended to suppress an overcurrent and a switch intended to switch an electric current route.

The bus bar has a length, a width, and a thickness. The length is a dimension in a direction intersecting an extension direction that passes through two coupling portions, which means portions of coupling to the lithium ion battery or the electrical connector. The width is a dimension in a direction intersecting the extension direction. The thickness is a dimension in a direction intersecting the extension direction and the width direction. The width and thickness are dimensions in directions intersecting the extension direction. The length is smaller than the width. The thickness is smaller than the width. The bus bar can be for example, plate-shaped. Specifically, the bus bar may be shaped like a flat plate for example, and may be bent entirely or bent at one or more portions. The bus bar has a plurality of surfaces, two of which are parallel surfaces that extend along both the length direction and the width direction. In other words, the bus bar has these two parallel surfaces that intersect the thickness direction. The width of the bus bar may be uniform, or may vary at some point. The bus bar can be for example, a product of press working A lead wire, for example, is not included in the bus bar.

The bus bar does not have an insulating coating, for example. The bus bar not having an insulating coating can provide a high heat dissipation ability adapted to a large electric current. The bus bar has a rigidity that allows the shape thereof to be maintained in the air while the bus bar is electrically connected and fixed at a plurality of portions (for example, at two portions), for example. The bus bar has a rigidity that can support the weight of the bus bar itself so as to keep the bus bar from substantially swinging, deforming, or :30 displacing, which may otherwise be caused by vibrations in traveling of the straddled vehicle, for example. The bus bar does not encompass, for example, a conductor that is deformed by the weight of the conductor itself and therefore cannot maintain a position of connection with a partner while the conductor is not connected to the partner. The bus bar has such a rigidity that its :15 positional relationship relative to the casing or to a device or component in the casing can be substantially maintained even while the straddled vehicle is traveling, for example. The bus bar has such a rigidity that two lithium ion batteries electrically connected to each other can be coupled as a single piece in a mechanical sense, too. The bus bar has a thickness that is able enough to provide the above-described rigidities. The bus bar, however, is not limited to the above, and may in part contain an insulating coating. The bus bar is coupled to the lithium ion battery and the electrical connector by, for example, welding. Alternatively, the bus bar may be coupled to the lithium ion battery and the electrical connector by bolts or nuts, for example. More specifically, the bus bar may be coupled to a terminal of the lithium ion battery and a terminal of the electrical connector by bolts or nuts, for example. In such a case, the width of the bus bar is larger than the diameter of the bolt or nut. The width of the bus bar can be larger than the diameter of the bolt or nut of the electrical connector, for example. The width of the bus bar can be larger than the width of the terminal of the lithium ion battery, for example. The bus bar, however, is not limited to the above, and for example, may have a width smaller than the width of the terminal of the lithium ion battery. The bus bar may be coupled by soldering, for example.

[00491 To a bus bar having a thickness of 0.5 mm or more for example, specifications with a strength based on industrial standards of bus bars are applicable. A bus bar having a thickness of 0.5 mm or more makes it easy to obtain a bus bar having a rigidity based on standards. A bus bar configured to output an electric current of 50 A for example has a cross-sectional area of about 20 square mm if based on the industrial standards. In this case, the width of the bus bar having a thickness of 0 5 mm or more can be as low as about 40 mm or less. Considering the battery size, the bus bar can be arranged with a high degree of freedom, with the interval between bus bars being suppressed. lb a bus bar having a thickness of 2 mm or more for example, specifications of components based on Japanese industrial standards of bus bars as well as the rigidity are applicable. Accordingly, a bus bar having a thickness of 2 mm or more makes it easy to obtain a higher rigidity so that both the shape of the bus bar itself and the interval between lithium ion batteries connected by the bus bar can easily be maintained. In addition, it is easy for a bus bar to obtain a strength based on industry standards.

The thickness of the bus bar is not particularly limited, and for example, 35 may be less than 0.5 mm.

[0050] The width and thickness of the bus bar are set such that charging is allowed with the electric current flowing along the single route formed by the series connection under the maximum charging voltage of 12 V or more and 60 V or less. For example, assuming an electric current of 50 A, the bus bar has a width and a thickness that gives the bus bar a cross-sectional area of 20 square mm or more.

[0051] The data communication terminal may be integrated with the electrical connector, for example. The data communication terminal, however, is not limited to this, and may be provided independently of the electrical connector.

The data for identifying the specifications of the straddled vehicle-battery pack is, for example, data representing the maximum charging electric current of the straddled vehicle-battery pack. The data is not particularly limited and, for example, may be data to identify the straddled vehicle-battery pack, or data to identify a type of the straddled vehicle-battery pack. In such a case, the external apparatus refers to a database based on the identifying data, to obtain information about the maximum charging electric current. The data communication terminal, for example, is built in the straddled vehicle-battery pack, and is electrically connected to the data output section that stores the data for obtaining the specifications. Here, the data output section connected to the data communication terminal may be, for example, mounted to the straddled vehicle at a location outside the straddled vehicle-battery pack. The data output section stores the data to obtain the specifications of the straddled vehicle-battery pack. The data output section can be built in the straddled vehicle-battery pack.

[0052] Connection encompasses a state where an electrical component can be interposed therebetween. Examples of the electrical component include a switch, a relay, a resistor, a connection terminal, and a fuse.

[0053] The straddled vehicle-battery pack receives and outputs electricity that is to be converted into motive power in order to increase the driving force of the straddled vehicle. This means that electricity that the straddled vehicle-battery pack outputs at a time of discharging is converted into motive power that contributes to increasing the driving force of the straddled vehicle. The electricity is converted into motive power by, for example, a motor. The motive power obtained by conversion is finally transmitted to a wheel.

For example, the straddled vehicle can be a pure electric motor vehicle that travels with electricity charged mainly in the straddled vehicle-battery pack. An increase of the driving force of the straddled vehicle depends on electricity charged in the straddled vehicle-battery pack. The straddled vehicle, however, is not particularly limited to the above, and may have an engine as an internal combustion engine. For example, it may be possible that electricity is converted into motive power by a motor, and is used to drive the engine, to consequently increase the driving force of the straddled vehicle. For example, it may be possible for a generator to be provided to an engine, in order that both electricity charged in the straddled vehicle-battery pack and electricity produced by the generator, be supplied to a motor.

[0054] The electric current breaker is an electrical component capable of switching between a state of transmitting an electric current and a state of breaking an electric current. The electric current breaker is an electrical component that switches from the state of transmitting an electric current to the state of breaking an electric current in accordance with, for instance, the flow amount of an electric current. An Example of such an electric current breaker may include a fuse and a breaker. The electric current breaker is not particularly limited to the above, and may be an electrical component that switches from the state of transmitting an electric current to the state of breaking an electric current in accordance with, for instance, a rider's manipulation. An example of such an electric current breaker may include a relay, a switch, and a service plug.

[0055] The terminology used herein is for defining particular embodiments only and is not intended to he limiting the teaching.

As used herein, the term "and/or" includes any and all combinations of 25 one or more of the associated listed items.

As used herein, the terms "including", "comprising", or "having", and variations thereof specify the presence of stated features, steps, operations, elements, components, and/or equivalents thereof, and can include one or more of steps, operations, elements, components, and/or their groups.

As used herein, the terms "attached", "coupled", and/or equivalents thereof are used in a broad sense, and include both of direct and indirect attachment and coupling unless otherwise specified.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of 35 ordinary skill in the art to which the present teaching belongs.

It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the present disclosure and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It will be understood that the description of the present teaching discloses a number of techniques and steps.

Each of these has individual benefit and each can also be used in conjunction with one or more, or in some cases all, of the other disclosed 10 techniques.

Accordingly, for the sake of clarity, this description will refrain from repeating every possible combination of the individual steps in an unnecessary fashion.

Nevertheless, Description and Claims should be read with the 15 understanding that such combinations are entirely within the scope of the present teaching and the claims.

Description will give an explanation about a novel straddled vehicle-battery pack.

In the description given below, for the purposes of explanation, 20 numerous specific details are set forth in order to provide a thorough understanding of the present teaching.

It will be apparent, however, that those skilled in the art may practice the present teaching without these specific details.

The present disclosure is to be considered as an exemplification of the 25 present teaching, and is not intended to limit the present teaching to the specific embodiments illustrated by drawings or descriptions below.

Advantageous Effects of Invention [00561 According to the present teaching, a straddled vehicle-battery pack 80 capable of being downsized with a simple configuration, and capable of charging within a short amount of time can be achieved.

Brief Description of Drawings

[00571 [FIG. Il A diagram schematically showing a straddled vehicle-battery 35 pack according to a first embodiment, a straddled vehicle equipped with the straddled vehicle-battery pack, and a comparative example.

[FIG. 2] A diagram showing on a larger scale the straddled vehicle-battery pack according to the first embodiment shown in FIG. 1.

[FIG. 3] A diagram more detailing the straddled vehicle shown in FIG. [FIG. 4] A diagram schematically showing a straddled vehicle-battery pack according to a second embodiment.

[FIG. 5] A perspective view of a bus bar of a straddled vehicle-battery pack according to a third embodiment.

[FIG. 6] A diagram schematically showing a straddled vehicle-battery 10 pack including the bus bars shown in FIG. 5.

Description of Embodiments

[0058] In the following, the present teaching will be described based on embodiments and with reference to the drawings.

[0059] [First Embodiment] FIG. 1 is a diagram schematically showing a straddled vehicle-battery pack according to a first embodiment, a straddled vehicle equipped with the straddled vehicle-battery pack, and a comparative example. The part (a-1) of FIG. 1 schematically shows the straddled vehicle equipped with the straddled vehicle-battery pack according to the first embodiment. The part (b-1) of FIG. 1 schematically shows the straddled vehicle-battery pack according to the first embodiment.

The part (a-2) of FIG. 1 schematically shows a straddled vehicle equipped with a straddled vehicle-battery pack according to the comparative 25 example. The part (b-2) of FIG. 1 schematically shows the straddled vehicle-battery pack according to the comparative example.

FIG. 2 is a diagram showing on a larger scale the straddled vehicle-battery pack according to the first embodiment shown in FIG. 1.

[0060] A straddled vehicle-battery pack 1 shown in the part (b-1) of FIG. 1 is a battery pack for use in a straddled vehicle 100. The straddled vehicle-battery pack 1 is a battery pack capable of charging and discharging. The straddled vehicle-battery pack 1 receives and outputs electricity that is to be converted into motive power for increasing a driving force of the straddled vehicle 100. The straddled vehicle-battery pack 1 is charged with a voltage equal to or less than a maximum charging voltage. The maximum charging voltage of the straddled vehicle-battery pack 1 is 12 V or more and 60 V or less. The maximum charging voltage of the straddled vehicle-battery pack 1 is 48 V, for example. The maximum charging voltage may be set to 14 V for example, or may be set to 36 V for example.

The straddled vehicle-battery pack 1 has a charge capacity of 2.5 Ah or 5 more. The straddled vehicle-battery pack 1, therefore, receives and outputs electricity for increasing the driving force of the straddled vehicle 100.

[0061] The straddled vehicle-battery pack 1 includes lithium ion batteries 11, a casing 12, an electrical connector 13, and bus bars 14a to 14f.

[0062] In the example shown in the part (n-1) of FIG. 1, the straddled 10 vehicle-battery pack 1 includes five lithium ion batteries 11. The lithium ion batteries 11 are not connected in parallel but connected in series with one another.

The number of lithium ion batteries 11 is set such that a maximum voltage across the series connection can be equal to or more than the maximum 15 voltage of the straddled vehicle-battery pack 1.

The lithium ion battery 11 is a battery capable of charging and discharging. The lithium ion battery 11 is a secondary battery that performs charging and discharging through a chemical reaction on electrodes. The lithium ion battery 11 has a positive electrode lla containing a lithium oxide.

The lithium ion battery 11 is a non-aqueous lithium ion battery using a non-aqueous electrolyte. The lithium ion battery 11 has a negative electrode llb containing at least any one selected from the group consisting of a spinel structure lithium titanate, a niobium-titanium-containing composite oxide, or graphite, for example. Here, the negative electrode llb of the lithium ion battery 11 is not particularly limited, and a negative electrode containing a substance other than the above may be adoptable.

The lithium ion battery 11 has a maximum charging electric current higher than that of a battery whose positive electrode contains another material, such as a lead-acid battery or a nickel-metal hydride battery. The all lithium ion battery 11 has a maximum continuous charge rate of 10 C or more. [0063] The casing 12 accommodates the lithium ion batteries 11. The casing 12 has a closed structure, for example.

Specifically, the casing 12 has a structure that makes the lithium ion batteries 11 invisible from the outside. This can suppress occurrence of a:15 situation where the lithium ion batteries 11 are contacted by a foreign body put in from the outside of the straddled vehicle-battery pack 1.

More specifically, the casing 12 has a waterproof structure, for example. In a case of the straddled vehicle-battery pack 1 being provided in the straddled vehicle 100 for example, the straddled vehicle-battery pack 1 may possibly be exposed to liquid such as water or oil. The casing 12 suppresses intrusion of the liquid. Accordingly, contact of the liquid with the lithium ion batteries 11 is suppressed.

[0064] The electrical connector 13, which is connected to a mating connector (not shown) disposed in a vehicle body 102 (see FIG. 3) of the straddled vehicle 100, transmits electric current received and outputted, to the vehicle body 102.

Electricity stored in the straddled vehicle-battery pack 1 is supplied to the vehicle body 102 of the straddled vehicle 100 through the electrical connector 13.

In regeneration, regenerated electricity is supplied from the vehicle body 102 of the straddled vehicle 100 to the straddled vehicle-battery pack 1 15 through the electrical connector 13.

The electrical connector 13 of this embodiment can also be connected to a charging apparatus, such as a charge station, disposed outside the straddled vehicle 100. When the straddled vehicle 100 is stopped, a mating connector disposed in an external charging apparatus is connected, instead of the mating connector disposed in the vehicle body 102 (see FIG. 3). Thus, the straddled vehicle-battery pack 1 is charged.

[0065] The bus bars 14a to 14f are conductors that connect the lithium ion batteries 11 and the electrical connector 13. The bus bars 14a to 14f are made of a metal.

The straddled vehicle-battery pack 1 has plural bus bars 14. Each of the bus bars 14a to 14f has a plate-like shape having a length L, a width W, and a thickness T. The bus bars 14a to 14f may have the same size and the same shape, or may have different sizes and different shapes. In one example, the bus bars 14a to 14e have the same size and the same shape. The bus bar 14f has a size and a shape different from those of the 14a to 14e.

In the drawings, for clarity of the drawings, the length L, the width W, and the thickness T of a part of the bus bars, 14e and 14f, are shown. Each of the bus bars 14a to 14e has its thickness T smaller than both its length L and width W. The bus bar 14f has its thickness T' smaller than both its length L' and width W'.

The bus bars 14a to 14f (hereinafter, also referred to as the bus bars 14) connect the lithium ion batteries 11 and the electrical connector 13 in series. The bus bars 14 connect the lithium ion batteries 11 in series without any parallel connection. Each of the bus bars 14 electrically connects a positive 5 electrode lla of one lithium ion battery 11 to a negative electrode llb of another lithium ion battery 11 different from the one lithium ion battery 11. Some of the bus bars 14 electrically connect the electrical connector 13 to the lithium ion batteries 11. The bus bars 14 are connected to the positive electrodes lla and the negative electrodes llb of the lithium ion batteries 11 10 via terminals (not shown).

Each of the bus bars 14 does not connect two or more positive electrodes lla disposed in two or more lithium ion batteries 11. Each of the bus bars 14 does not connect two or more negative electrodes llb disposed in two or more lithium ion batteries 11. The lithium ion batteries 11 are not connected in parallel.

Each bus bar 14 has no insulating coating. Each bus bar 14 has its conductor portion exposed to the outside. The bus bars 14 can provide a high heat dissipation ability adapted to a large electric current.

The bus bars 14 are coupled, by welding for example, to the lithium ion 20 batteries 11 and the electrical connector 13.

Each of the bus bars 14a to 14f has an electrical resistance lower than that of a wire having a conductor diameter equal to the thickness T and having a length equal to the length L of the bus bars 14a to 14e, for example. When a charging electric current of the lithium ion batteries 11 connected in series flows through the bus bars 14a to 14f, an amount of heat generated by the bus bars 14a to 14f themselves is further suppressed.

In a circuit including the bus bars 14a to llf, the lithium ion batteries 11, and the electrical connector 13; a total resistance, which means the total sum of resistances of the bus bars 14a to llf, is lower than a charge resistance of one lithium ion battery 11. The charge resistance of the lithium ion battery 11 is obtained from the maximum charging electric current relative to the maximum charging voltage of the lithium ion battery 11. A total series resistance of the bus bars 14a to llf is lower than the charge resistance of one lithium ion battery 11. Thus, the amount of heat generated from the entire :35 bus bars at a time of charging is smaller than the amount of heat generated from one lithium ion battery 11. The bus bars 14a to llf are dispersedly arranged within the straddled vehicle-battery pack 1. Accordingly, heat generated through the bus bars 14a to llf due to an electric current flowing through the bus bars 14a to llf is dispersed within the straddled vehicle-battery pack 1. Consequently, concentration of heat generated in the straddled vehicle-battery pack 1 can be suppressed.

[00661 The lithium ion batteries 11 included in the straddled vehicle-battery pack 1 of this embodiment are not connected in parallel but connected in series with one another. There are variations in internal resistance between the lithium ion batteries 11. However, electric currents flowing through the respective lithium ion batteries 11 connected in series are substantially equal irrespective of differences in internal resistance. It therefore is easy to keep a balance between charging amounts of the respective lithium ion batteries 11.

For example, in a case where charging is started when the charging amount of each lithium ion battery 11 is zero, the accumulated amounts of electric currents in the respective lithium ion batteries 11 at an arbitrary time are substantially equal. That is, the charging amounts of the respective lithium ion batteries 11 are substantially equal. Also in discharging of the lithium ion batteries 11, substantially equal electric currents flow through the respective lithium ion batteries 11. Thus, the charging amounts of the respective lithium ion batteries 11 at an arbitrary time are substantially equal. In charging, therefore, the lithium ion batteries 11 reach a full charge state substantially at the same time.

This makes it possible to keep a balance between charging amounts of the respective lithium ion batteries 11 without a control device for monitoring and controlling states of lithium ion batteries connected in parallel. Accordingly, the straddled vehicle-battery pack 1 can be downsized with a simple configuration.

A standard working voltage of each lithium ion battery 11 is 2.3 V, for example. Each lithium ion battery 11 can be charged with a voltage higher:30 than the standard working voltage, however. Each lithium ion battery 11 is charged with a voltage of 3 V or more, for example.

[00671 While the lithium ion batteries 11 are configured to be not connected in parallel but connected in series with each other, the maximum voltage that the straddled vehicle-battery pack 1 can charge is 12 V or more and 60 V or less.

:15 In this configuration, the maximum voltage applied across a group of the lithium ion batteries 11 connected in series is 12 V or more and 60 V or less.

[0068] Since the maximum voltage that the straddled vehicle-battery pack 1 can charge is 12 V or more, a design is allowed in which it is in direct electrical connection with an ordinary electrical component mounted to the straddled vehicle 100. Since the maximum voltage that the straddled vehicle-battery 5 pack 1 can charge is 12 V or more, a design is allowed in which a motor 105 generally mounted to the straddled vehicle 100 is used as a motor 105 that receives a supply of charged electricity. Since the maximum voltage that the straddled vehicle-battery pack 1 can charge is 12 V or more, the motor 105 that receives a supply of charged electricity can easily increase the driving force of 10 the straddled vehicle 100.

[0069] The straddled vehicle-battery pack 1 operates in a range that belongs to "extra low voltage" (extra low voltage: ELV, or safety extra low voltage: SELV) according to the IEC (International Electrotechnical Commission) standard No. IEC60950. A potential difference at any node within the straddled vehicle-battery pack 1 does not exceed 60 V. This is why the "operational insulation" range is enough as an insulation level of each node used in the battery pack. An insulation structure of the straddled vehicle-battery pack 1, whose voltage is a low voltage, can be simplified as compared to a high-voltage one.

[0070] As the lithium ion battery 11, for instance, a lithium ion battery 11 having a charge capacity of 5 Ah or more and 40 Ah or less is adoptable. In a case where such a lithium ion battery 11 has a maximum charging voltage of 3 V, the straddled vehicle-battery pack 1 including five lithium ion batteries 11 connected in series has a maximum charging voltage of 15 V. In a case where, for example, the lithium ion battery 11 has a charge capacity of 5 Ah and a maximum continuous charge rate of 10 C, the lithium ion battery 11 has a maximum continuous charging electric current of 50 A. In a case where, for example, the lithium ion battery 11 has a charge capacity of 20 Ah and a maximum continuous charge rate of 10 C, the lithium ion battery 11 has a maximum continuous charging electric current of 200 A. Thus, it is not easy to grasp the ability to full-charge a battery based only on the charging electric current. This is because the ability of the battery to reach full-charge varies depending not only on the charging electric current but also on the charge capacity. In the Description herein, therefore, an indication using a :35 charge rate with a difference in charge capacity taken into account is employed to indicate the ability of the battery to reach full-charge.

[0071] As mentioned above, the voltage applied across the plural lithium ion batteries 11 connected in series is a low voltage belonging to the "extra low voltage". In this case, the number of lithium ion batteries 11 connected in series can be reduced as compared to a case where, for example, a voltage higher than a voltage belonging to the "extra low voltage" is applied. For example, the straddled vehicle-battery pack 1 of this embodiment includes five lithium ion batteries 11 connected in series.

As a result, variations in charging ability characteristics between the respective lithium ion batteries 11 included in the straddled vehicle-battery pack 1 of this embodiment can be reduced as compared to a case of, for example, using many batteries for adaptation to high voltages higher than the "extra low voltage".

Accordingly, the straddled vehicle-battery pack 1 of this embodiment can more easily keep a balance between charging amounts of the respective 15 lithium ion batteries 11, without a control device such as a battery management system (BMS).

[0072] The lithium ion batteries 11 of the respective lithium ion batteries 11 included in the straddled vehicle-battery pack 1 of this embodiment are connected by bus bars 14a to 14f having a low resistance. Thus, in the straddled vehicle-battery pack 1, a high maximum continuous charge rate can be obtained without any parallel connection of the plural lithium ion batteries 11.

For example, the straddled vehicle-battery pack 1 having a maximum continuous charge rate of 10 C or more is able to charge 50% or more of the charge capacity of the straddled vehicle-battery pack 1 within three minutes. This makes it possible that, for example, an electric motor vehicle equipped with the straddled vehicle-battery pack 1 of this embodiment is charged in a time length near a time length required for replenishment of a liquid fuel at a conventional or existing gas station. A charge station is therefore occupied for a short time.

The straddled vehicle-battery pack 1 of the embodiment may alternatively be configured to have a maximum continuous charge rate of less than 10 C. In the above, the amount of electricity charged is assumed to be, for:35 example, 50% of the charge capacity of the straddled vehicle-battery pack 1, because it is often the case that the straddled vehicle 100, which does not have an auxiliary power supply such as an engine generator, is normally charged with a sufficient margin relative to the 0% charging amount. For instance, even when the charging amount of the straddled vehicle-battery pack 1 is more than 50%, the straddled vehicle 100 is charged frequent times (such as when the rider is at home).

If it is possible that 50% or more of the straddled vehicle-battery pack 1 is charged within three minutes for example, the straddled vehicle-battery pack 1 is charged more frequently. To be specific, in one conceivable usage, if there is a charge station in a travel route, the straddled vehicle 100 makes a stopover at the charge station for a few minutes to be charged, even though the charging amount of the straddled vehicle-battery pack 1 is 70% or more.

In a case of a charge station having two or more charging apparatuses for example, it is possible to distinguish a charging apparatus (fast lane) dedicated for a vehicle that will complete charging in a few minutes from a charging apparatus for the other vehicles. In such a case, a particular vehicle that will complete charging in a few minutes does not have a long waiting time and needs to stay only for a short time before its charging is completed.

[00731 The straddled vehicle-battery pack 1 of this embodiment includes the lithium ion batteries 11 that are not connected in parallel but connected in series. Therefore, the maximum continuous charge rate and the maximum charging electric current of the straddled vehicle-battery pack 1 cannot exceed the maximum continuous charge rate and the maximum charging electric current of the lithium ion batteries 11. In other words, the maximum continuous charge rate and the maximum charging electric current of the straddled vehicle-battery pack 1 are restricted mainly by the maximum continuous charge rate and the maximum charging electric current of the lithium ion batteries 11.

Examples of a lithium ion battery 11 having a maximum continuous charge rate of 10 C or more include: a lithium ion battery having a charge capacity of 40 Ah or less and a maximum charging electric current of 400 A; a lithium ion battery having a charge capacity of 20 Ah or less and a maximum charging electric current of 200 A; a lithium ion battery having a charge capacity of 10 Ah or less and a 35 maximum charging electric current of 100 A; or a lithium ion battery having a charge capacity of 5 Ah or less and a maximum charging electric current of 50 A. [0074] Selecting a lithium ion battery having a charge capacity of 5 Ah or less makes it possible to provide a maximum continuous charge rate of 10 C or more, even when a charging electric current that can be supplied from a charging apparatus is as small as 50 A. [0075] A maximum distance over which the straddled vehicle 100 (see FIG. 3) can travel with the charged electricity depends on a total charging amount of the straddled vehicle-battery pack 1. The total charging amount of the straddled vehicle-battery pack 1 is in proportion to the number of built-in lithium ion batteries 11. Since the lithium ion batteries 11 are not connected in parallel but connected in series, it is possible that the number of lithium ion batteries 11 is set independently of the maximum charging electric current and the maximum continuous charge rate. The number of lithium ion batteries 11 included in the straddled vehicle-battery pack 1 is equal to the number of series connections of the lithium ion batteries 11.

In designing the straddled vehicle 100, the maximum distance over which the straddled vehicle 100 can travel can be set by using the number of lithium ion batteries 11 included in the straddled vehicle-battery pack 1.

The charging voltage of the straddled vehicle-battery pack 1 is in proportion to the number of lithium ion batteries 11. That is, the product of a charging voltage of one lithium ion battery 11 and the number of lithium ion batteries 11 is substantially equal to the charging voltage of the straddled vehicle-battery pack 1.

The maximum charging voltage of the straddled vehicle-battery pack 1 is 20 V or more and 60 V or less. Thus, the number of lithium ion batteries 11 is set such that the product mentioned above can be 60 V or less.

[0076] A voltage that is applied to the straddled vehicle-battery pack 1 in order to cause the aforementioned maximum charging electric current to flow through the straddled vehicle-battery pack 1 is divided by the number of lithium ion batteries 11 connected in series, and as a result, a voltage substantially applied to each lithium ion battery 11 is obtained. The obtained voltage is divided by the maximum charging electric current, and as a result, an internal resistance of each lithium ion battery 11 is obtained.

Each of the bus bars 14a to 14f has a plate-like shape. A total resistance of the bus bars 14a to 14f is set lower than the internal resistance of each lithium ion battery 11 mentioned above. For example, the total resistance can be reduced by increasing the width W or the thickness T of the bus bars 14a to 14f.

Setting the total resistance of the bus bars 14a to 14f to be lower than 5 the internal resistance of each lithium ion battery 11 can suppress an influence of the resistance of the bus bars 14 on the voltage, the electric current, and the maximum continuous charge rate of the straddled vehicle-battery pack 1.

[0077] As described above, in the straddled vehicle-battery pack 1 of this embodiment, the lithium ion batteries 11 are connected to one another by the bus bars 14b to 14e, and furthermore the lithium ion batteries 11 are connected to the electrical connector 13 by the bus bars 14a, 14f. Elimination of parallel connection of the lithium ion batteries 11 makes it possible to keep a balance between charging amounts of the respective lithium ion batteries 11, with a circuit simpler than a centralized control device such as a battery management controller (BMC), or without such a circuit. Moreover, the insulation structure can be simplified. Accordingly, the straddled vehicle-battery pack 1 having a simple configuration and being small in size can be achieved. The straddled vehicle-battery pack 1 can be charged within a short amount of time, without parallel connection of the plural lithium ion batteries 11.

[0078] For example, a straddled vehicle-battery pack 91 according to the comparative example shown in the part (2-b) of FIG. 1 may be conceivable as a straddled vehicle-battery pack having a maximum charging voltage of 60 V or less and configured to receive electricity for increasing a driving force of a straddled vehicle. The straddled vehicle-battery pack 91 of the comparative example has a combination of parallel connection and series connection. An electric current flowing through bus bars 914b to 914e, which connect lithium ion batteries 911 to one another, is small. In the straddled vehicle-battery pack 91 of the comparative example, however, the shapes and arrangement of the bus bars 914b to 914e are more complicated as compared to the straddled vehicle-battery pack 1 of this embodiment shown in the part (1-h) of FIG. 1. The straddled vehicle-battery pack 91 of the comparative example is large in size. Consequently, the straddled vehicle 910 equipped with the straddled vehicle-battery pack 91 tends to be large in size, too.

[0079] In this respect, the straddled vehicle-battery pack 1 having a simple 85 configuration and being small in size, and capable of charging within a short amount of time, can be achieved.

[00801 FIG. 3 is a diagram more detailing an outline of the straddled vehicle shown in FIG. 1.

The straddled vehicle 100 shown in FIG. 3 has the straddled vehicle-battery pack 1. The straddled vehicle 100 includes the vehicle body 102 and wheels 103a, 103h. The vehicle body 102 is provided with a motor control device 104 and the motor 105. The vehicle body 102 includes a saddle 107 and a handle bar 108 for steering. The saddle 107 is configured to have a rider sit straddling thereon. The handle bar 108 for steering is disposed so as to extend in a left-right direction of the straddled vehicle 100. The straddled vehicle 100 is, as a lean vehicle, configured to make a turn in such a manner that at a time of turning, a rider who grips the handle bar 108 shifts his/her weight so as to make the straddled vehicle 100 lean toward the inside of a curve. The straddled vehicle 100 does not include an engine as an internal combustion engine. The straddled vehicle 100 is configured without inclusion of a control device. The control device as recited herein is configured to: acquire at least one parameter from among an electric current, a voltage, or a temperature detected from each of the plural lithium ion batteries 11 included in the straddled vehicle-battery pack 1; and based on the at least one parameter acquired, change the voltage and/or the electric current of at least one lithium ion battery 11 of the plural lithium ion batteries 11. Such a control device is not disposed in the straddled vehicle-battery pack 1, either.

The rear wheel 103b is a driving wheel. The motor 105 drives the wheel 103h with electricity supplied from the straddled vehicle-battery pack 1. As the wheel 103b is driven, the straddled vehicle 100 travels.

Electricity in the straddled vehicle-battery pack 1 is supplied to the motor 105 via the motor control device 104. The straddled vehicle-battery pack 1 is connected to the motor control device 104 via the electrical connector 13. The motor control device 104 controls a supply of electricity from the straddled vehicle-battery pack 1 to the motor 105 via the mating connector, and a supply of electricity from the motor 105 to the straddled vehicle-battery pack 1 via the mating connector. That is, the straddled vehicle-battery pack 1 is connected to the vehicle body 102 of the straddled vehicle 100 via the electrical connector 13. An electric current is transmitted from the straddled vehicle-battery pack 1 to the motor control device 104 via the electrical connector 13.

When, for example, braking is applied to the straddled vehicle 100 by regenerative braking of the motor 105, electricity generated in the motor 105 is supplied to the straddled vehicle-battery pack 1 via the motor control device 104. At this time, the straddled vehicle-battery pack 1 is charged.

[0081] The straddled vehicle 100 shown in FIG. 3 has a function of being charged with electricity supplied from the outside of the straddled vehicle 100. More specifically, the straddled vehicle-battery pack 1 has a function of being charged with electricity supplied from the outside of the straddled vehicle 100. For example, the mating connector disposed in the motor control device 10 104 is disconnected from the electrical connector 13, and a connector of a charging apparatus provided outside the straddled vehicle 100 is connected to the electrical connector 13. The connector of the charging apparatus provided outside is, for example, a connector disposed in a charging apparatus at a charge station. As the connector of the charging apparatus, for example, a 15 connector of a charging apparatus that is installed in an ordinary home and that uses a commercial power supply may be employed.

[0082] The plural lithium ion batteries 11 are connected to one another by the bus bars 14, and furthermore the electrical connector 13 is connected by the bus bars 14, too, and therefore the straddled vehicle-battery pack 1 can be charged with a large electric current without parallel connection of plural lithium ion batteries 11, as has been described with reference to the part (1-b) of FIG. 1. For example, the straddled vehicle-battery pack 1 has a maximum continuous charge rate of 10 C or more. It however may be possible that the straddled vehicle-battery pack 1 has a maximum continuous charge rate of 20 C or more, or 40 C or more for example, in accordance with specifications of the lithium ion batteries 11 and bus bars 14 suited to the specifications.

[0083] The straddled vehicle-battery pack 1 having a maximum continuous charge rate of 10 C or more makes it possible that, for example, 50% or more of the charge capacity of the straddled vehicle-battery pack 1 is charged within three minutes. Accordingly, the straddled vehicle 100 does not need to occupy a charge station for a long time for charging.

[0084] [Comparative Example] To be able to charge the same amount of energy (electric charges) as in the embodiment in the same charge time as in the embodiment while reducing:15 an electric current flowing through bus bars in a straddled vehicle-battery pack configured with series connection without any parallel connection; a first method may be conceivable in which the number of lithium ion batteries connected in series is increased. This is because the amount of energy (electric charges) is in proportion to the product of an electric current and a voltage of the pack. Even if the charging amount of each individual lithium ion battery is smaller than the charging amount in a full charge state, energy (electric charges) can be compensated for by increasing the number of lithium ion batteries connected in series. In this regard, however, increasing the number of lithium ion batteries connected in series so as to increase energy involves an increase in a charging voltage. As a result, a maximum charging voltage may be beyond a range of 12 V or more and 60 V or less. Moreover, increasing the number of lithium ion batteries connected in series so as to increase energy involves an increase in output voltage of the straddled vehicle-battery pack. This requires a motor control device and a motor to have an increased maximum voltage. Furthermore, increasing the number of lithium ion batteries makes the straddled vehicle-battery pack larger in size. Consequently, the straddled vehicle 910 equipped with the straddled vehicle-battery pack 91 becomes larger in size, too.

[00851 To be able to charge the same amount of energy (electric charge) as in the embodiment in the same charge time as in the embodiment while reducing an electric current flowing through bus bars; a second method may be conceivable in which the number of lithium ion batteries connected in parallel is set to more than one. Parallel connection has less voltage problems as compared to a case of a series voltage. Thus, increasing the charge rate in parallel connection is simple in principle. In a case of parallel connection, however, the straddled vehicle-battery pack becomes larger in size.

First, in a case of increasing the number of lithium ion batteries connected in parallel, the number of lithium ion batteries is twice, three times, ... as compared to a case of no parallel connection. Thus, the volume of the lithium ion batteries themselves is increased. A lifetime of a lithium ion battery is easily influenced by the temperature. It therefore is necessary that as the number of lithium ion batteries increases, intervals between the respective lithium batteries are made larger so as to increase the amount of heat dissipation. The volume of the entire plural lithium ion batteries including the intervals increases.

Second, coexistence of series connection and parallel connection makes wiring complicated. A space for accommodating complicated wiring is therefore required.

Finally, in a case of connecting lithium ion batteries in parallel, a charging amount varies depending on variations in internal resistance between the respective lithium ion batteries. To suppress variations in charging amount, a control device for monitoring and controlling states of the lithium ion batteries connected in parallel is necessary.

[00861 The lithium ion batteries 911 shown in the part (h-2) of FIG. 1 are connected in parallel, and are in series. The configuration includes two parallels and five series's. In the entire straddled vehicle-battery pack 91 of the comparative example, a maximum continuous charge rate equivalent to that of the embodiment shown in the part (b-1) of FIG. 1 is achieved.

The bus bars 914a to 914f, which connect the lithium ion batteries 911, have complicated shapes because the connection includes both parallel connection and series connection. For example, the thickness of the bus bars 914b to 914, which connect the lithium ion batteries 911 to one another, can be smaller than those of the embodiment shown in the part 0o-H of FIG. 1. However, the bus bars 914a to 914f, which connect the lithium ion batteries 911, have complicated shapes because the connection includes both parallel connection and series connection. Arrangement of the bus bars 914a to 914f is complicated. Consequently, a space for wiring of the bus bars 914a to 914f is wider than that of the embodiment shown in the part 6-H of FIG. 1.

In addition, control circuits 916, 917 are provided in order to suppress variations in charging amount between the respective lithium ion batteries 911 connected in parallel. The control circuits 916, 917 include individual control sections 917 and a central control section 916. Each individual control section 917 has a circuit that detects an electric current of each lithium ion battery 911, and that limits the electric current. Each individual control section 917 supplies a detection result, as electric current data, to a control device. The central control section 916 calculates a charging amount of each lithium ion battery 911, from the electric current data of each lithium ion battery 911. The central control section 916 causes each individual control section 917 to limit the electric current of the corresponding lithium ion battery 911, in accordance with a calculation result. In this manner, the central control section 916 performs a control so as to keep a part of the plural lithium ion batteries 911 from overcharging.

[0087] The straddled vehicle-battery pack 91 shown in the part (h-2) of FIG. 1 is larger in size than the straddled vehicle-battery pack 1 according to the embodiment shown in the part (b-1) of FIG. 1, for example. Thus, the straddled vehicle 910 shown in the part (a-2) of FIG. 1, which is equipped with the straddled vehicle-battery pack 91, is larger than the straddled vehicle 100 according to the embodiment shown in the part (a-1) of FIG. 1.

[0088] The straddled vehicle-battery pack 1 of this embodiment shown in the part (b-1) of FIG. 1 is smaller than the straddled vehicle-battery pack 1 according to the comparative example shown in the part (b-2) of FIG. 1, for example. Thus, the straddled vehicle 100 shown in the part (a-1) of FIG. 1, which is equipped with the straddled vehicle-battery pack 1 of this embodiment, is smaller than the straddled vehicle 910 according to the comparative example shown in the part (a-2) of FIG. 1.

[0089] [Second Embodiment] FIG. 4 is a diagram schematically showing a straddled vehicle-battery pack according to a second embodiment.

[0090] A straddled vehicle-battery pack 21 according to this embodiment is different from the straddled vehicle-battery pack 1 according to the first embodiment, in that it further includes a charging-dedicated connector 15 and an electric current breaker 18. In addition, an electrical connector 13 includes a data communication terminal 13a. The charging-dedicated connector 15 includes a data communication terminal 19b, too. The other configurations will be given the same reference signs as given to the straddled vehicle-battery pack 1 shown in the part (1-a) of FIG. 1, and some of descriptions of the other configurations will be omitted.

[0091] Connected to the charging-dedicated connector 15 of the straddled vehicle-battery pack 21 shown in FIG. 4 is a connector of a charging apparatus disposed outside a straddled vehicle 100. The charging-dedicated connector 15 is connected in parallel with the electrical connector 13 relative to a group of lithium ion batteries 11. The charging-dedicated connector 15 is used only when the straddled vehicle-battery pack 21 is charged with electricity supplied from the outside of the straddled vehicle 100.

:15 [0092] The data communication terminal 13a outputs, to the outside of the straddled vehicle-battery pack 1, data for identifying specifications of the straddled vehicle-battery pack 1. The data communication terminal 13a is integrated with the electrical connector 13. The data communication terminal 18a is electrically connected to a data output section 17. The data output section 17 stores data for identifying electrical specifications of the straddled 5 vehicle-battery pack 1. The data output section 17 is built in the straddled vehicle-battery pack 1. While the data communication terminal 13a is electrically connected to the outside of the straddled vehicle-battery pack 1, the data output section 17 outputs specification data stored therein, via the data communication terminal 13a. The data communication terminal 13a outputs 10 data for discriminating the straddled vehicle-battery pack 1, as the specification data for identifying the specifications.

For example, an external apparatus of the straddled vehicle-battery pack 1 can obtain information on a maximum charging electric current of the straddled vehicle-battery pack 1, based on the specification data outputted via the data communication terminal 13a. For example, a motor control device 104 disposed in a vehicle body 102 (see FIG. 3) obtains information on a maximum charging electric current that can be supplied to the straddled vehicle-battery pack 1 with regenerative braking of the straddled vehicle 100, based on the specification data outputted via the data communication terminal 13a.

[00931 The data communication terminal 19b outputs, to the outside of the straddled vehicle-battery pack 1, specification data for identifying specifications of the straddled vehicle-battery pack 1. The data communication terminal 19b is integrated with the charging-dedicated connector 15. The data communication terminal 19b is electrically connected to the data output section 17. A charging apparatus disposed outside the straddled vehicle 100 can obtain information on a maximum charging electric current of the straddled vehicle-battery pack 1 with reference to a database for example, based on the specification data outputted via the data communication terminal 19h. For example, a charging apparatus at a charge station (not shown) obtains information on a maximum charging electric current that can be supplied to the straddled vehicle-battery pack 1, based on the specification data outputted via the data communication terminal 19b.

[00941 The straddled vehicle-battery pack 21 includes the electrical connector:15 13 and the charging-dedicated connector 15. This allows the straddled vehicle-battery pack 21 to be charged while the vehicle body 102 of the straddled vehicle 100 is kept connected to the electrical connector 13. Accordingly, a charge operation can be easy, and moreover the degree of freedom in an installation position of the straddled vehicle-battery pack 21 can be increased.

[00951 Each lithium ion battery 11 has a negative electrode llb containing at least any one selected from the group consisting of a spinel structure lithium titanate, a niobium-titanium-containing composite oxide, or graphite. Each lithium ion battery 11, therefore, has wide allowable ranges of a charging voltage and a discharging voltage. Accordingly, it is easy to keep a balance between charging amounts of the respective lithium ion batteries, without providing a control device such as a battery management system (BMS).

[00961 The electric current breaker 18 of the straddled vehicle-battery pack 21 allows conduction of an electric current through the lithium ion batteries 11, or blocks the electric current.

The electric current breaker 18 of the straddled vehicle-battery pack 21 is configured to be brought into an on-state upon connection of a mating connector to the electrical connector 13 or to the charging-dedicated connector 15, for example. The electric current breaker 18 is configured to be brought into an on-state by an electric current conducted through a mating connector, for example. As means for creating the on-state, a device that detects physical connection or detects a signal received from a mating device upon connection may be provided, for example.

[00971 The configuration of this embodiment can suppress unintentional flow-out of the electric current of the lithium ion batteries 11 to the outside through the electrical connector 13 or the charging-dedicated connector 15. It therefore is possible to suppress the following situation: during an operation of detaching or attaching the straddled vehicle-battery pack 1 from or to the vehicle body 102 (see FIG. 3) for example, the electrical connector 13 or the charging-dedicated connector 15 is unintentionally in contact with a conductor of some kind at a location outside the straddled vehicle-battery pack 1, and as a result, a large electric current caused by short-circuiting welds the conductor to the electrical connector 13 or the charging-dedicated connector 15.

Accordingly, a situation where, for example, an external conductor is welded to the electrical connector 13 or the charging-dedicated connector 15 can 35 be suppressed with a simple configuration, without providing a control device such as a battery management system (BMS).

[0098] [Third Embodiment] FIG. 5 is a perspective view of a bus bar of a straddled vehicle-battery pack according to a third embodiment.

A bus bar 314b shown in FIG. 5 has a plate-like shape. The bus bar 5 314h does not have a flat-plate shape, however. The bus bar 314h has bent portions. The bus bar 314b is formed by a flat plate having undergone a bending process.

The bus bar 314h has a length L, a width W, and a thickness T. The thickness T is smaller than both the length L and the width W. [0099] FIG. 6 is a diagram schematically showing a straddled vehicle-battery pack including the bus bars shown in FIG. 5.

A straddled vehicle-battery pack 31 shown in FIG. 6 includes bus bars 314a to 314f.

The bus bars 314b to 314e have the same shape as the shape shown in FIG. 5. The straddled vehicle-battery pack 31 has lithium ion batteries 11 that are batteries identical to those shown in the part (1-b) of FIG. 1. The lithium ion batteries 11 of the straddled vehicle-battery pack 31, however, are arranged in a different direction than the arrangement direction shown in the part (1-b) of FIG. 1. In the straddled vehicle-battery pack 31, all the lithium ion batteries 11 are arranged with their positive electrodes lla toward the same direction.

The other points are the same as in the first embodiment shown in the part (1-h) of FIG. 1.

[0100] The present teaching is not limited to the examples given above, and for 25 instance, the following configurations (8) to (13) may be adoptable. The above-described embodiments may be mentioned as embodiments of the (8) to (13) below.

[0101] (8) In the straddled vehicle-battery pack according to any one of (1) to (5), all the bus bar is structured to have no insulating coating and have a conductor metal exposed.

[0102] The foregoing configuration can provide a high heat dissipation ability adapted to a large electric current.

[0103] (9) In the straddled vehicle-battery pack according to any one of (1) to :35 (5), the casing has a fluid-tight structure.

[01041 With the foregoing configuration, even when the straddled vehicle-battery pack 1 may possibly be exposed to liquid such as water or oil, the casing suppresses intrusion of the liquid. Accordingly, contact of the liquid with the lithium ion batteries is suppressed.

[01051 (10) In the straddled vehicle-battery pack according to any one of (1) to (5), the bus bar has a total resistance lower than a charge resistance of one lithium ion battery [01061 The foregoing configuration suppresses an influence of the resistance of 10 the bus bar on the voltage, the electric current, and the maximum continuous charge rate of the straddled vehicle-battery pack 1.

[01071 (11) In the straddled vehicle-battery pack according to any one of (1) to (5), the data communication terminal is integrated with the electrical connector.

[01081 With the foregoing configuration, communication via the data communication terminal is enabled by connection of the electrical connector to a mating connector. An operation for the connection is simple.

[01091 (12) In the straddled vehicle-battery pack according to any one of (1) to (5), the data communication terminal is integrated with the charging-dedicated connector.

[01101 With the foregoing configuration, communication via the data communication terminal is enabled by connection of the charging-dedicated 25 connector to a mating connector. An operation for the connection is simple.

Reference Signs List [01111 1, 21, 31 straddled vehicle-battery pack 11 lithium ion battery 12 casing 13 electrical connector 14 (14a to 140, 314a to 314f bus bar 18 electric current breaker 13a. 19b data communication terminal 100 straddled vehicle 102 vehicle body 104 motor control device motor 107 saddle 108 handle bar

Claims

CLAIMS[Claim 1] A straddled vehicle-battery pack for use in a straddled vehicle, the 5 straddled vehicle-battery pack comprising: plural lithium ion batteries; a casing that accommodates the plural lithium ion batteries; and an electrical connector attached to the casing, the electrical connector being connected to a mating connector that is disposed in a vehicle body of the 10 straddled vehicle, the electrical connector being configured to transmit electric current received from and outputted to the vehicle body, the straddled vehicle-battery pack having a charge capacity of 2.5 Ah or more, a maximum charging voltage of 12 V or more and 60 V or less, and a plate-shaped bus bar for connecting the electrical connector and the plural lithium ion batteries in series without any parallel connection, to be able to receive and output electricity that is to be converted into motive power for increasing a driving force of the straddled vehicle, the plate-shaped bus bar having such a width and a thickness that charging of electricity for increasing the driving force of the straddled vehicle can be made possible with an electric current flowing along a single route that is formed by the series connection under the maximum charging voltage of 12 V or more and 60 V or less.
[Claim 2] The straddled vehicle-battery pack according to claim 1, wherein each of the plural lithium ion batteries has an independent negative electrode, the independent negative electrode containing at least any one selected from the group consisting of a spinel structure lithium titanate, a niobium-titanium-containing composite oxide, and graphite, the bus bar connecting the independent negative electrode to a positive electrode or a negative electrode without electrically connecting the independent negative electrode to another independent negative electrode, to provide a series-connection structure of the plural lithium ion batteries without any parallel connection.
[Claim 3] The straddled vehicle-battery pack according to claim 1 or 2, further comprising an electric current breaker that breaks an electric current flowing through the plural lithium ion batteries, the electric current breaker being connected in series with the electrical connector and the plural lithium ion batteries.
[Claim 4] The straddled vehicle-battery pack according to any one of claims 1 to 3, wherein a data output section is provided inside the casing, the data output section being configured to output specification data for identifying electrical 10 specifications of the straddled vehicle-battery pack, and the electrical connector includes a data communication terminal for outputting the specification data to the outside of the straddled vehicle-battery pack.
[Claim 5] The straddled vehicle-battery pack according to any one of claims 1 to 4, wherein a charging-dedicated connector is attached to the casing, the charging-dedicated connector being configured to take a charging electric current directly into the straddled vehicle-battery pack from the outside of the straddled vehicle in which the straddled vehicle-battery pack is installed.
[Claim 6] A straddled vehicle comprising: the straddled vehicle-battery pack according to any one of claims 1 to 5; a mating connector configured to be connected to the electrical 25 connector of the straddled vehicle-battery pack; a driving wheel; a motor control device configured to control a supply of electricity from the straddled vehicle-battery pack to a motor via the mating connector and a supply of electricity from the motor to the straddled vehicle-battery pack via 30 the mating connector; and the motor configured to drive the driving wheel with electricity supplied from the motor control device as well as to generate electricity by the driving wheel being driven, wherein the straddled vehicle is configured without inclusion of any control 85 device that is configured to acquire at least one parameter from among an electric current, a voltage, or a temperature detected from each of the plural lithium ion batteries, and based on the at least one parameter acquired, to change a voltage and/or an electric current of at least one lithium ion battery of the plural lithium ion batteries.
[Claim 7] The straddled vehicle according to claim 6, further comprising: a handle bar for steering, disposed extending in a left-right direction of the straddled vehicle; and a saddle configured to have a rider sit straddling thereon, the straddled vehicle being configured, as a lean vehicle, to make a turn 10 in such a manner that at a time of turning, a rider who grips the handle bar shifts their weight so as to make the straddled vehicle lean toward the inside of a curve.