BATTERY-BASED CHARGING EQUIPMENT, BATTERY-BASED CHARGING SYSTEMS, AND HIGH-CURRENT LITHIUM-ION BATTERIES

Abstract

The invention proposes a charging system, a charge-in-charge device, and a high-current lithium-ion battery driver that can be reduced in size with a simple construction, and allows for further shortening of charging times to charge high-current lithium-ion batteries with a charging capacity sufficient to drive electrical equipment. The charge-in-charge device comprises a charging connector, a high-current lithium-ion battery with integrated discharge, which satisfies high-current discharge parameters, a compatible battery detection and switching device, and a high-current current supply path.The battery compatibility detection section and the switching section, which are located in the high-current current supply path, are structured to switch to the ON state in response to the detection that a high-current lithium-ion battery with integrated discharge, satisfying the maximum operating voltage and high-current charging parameters, is connected to the charging connector, to allow high current to be supplied from the high-current lithium-ion battery with integrated discharge through the high-current current supply path without any voltage converter interference, so that the high-current lithium-ion battery with integrated discharge is charged with high current. High current refers to a current corresponding to a rate of 10 C or more for a charging capacity of 2.5Ah.

Description

Storage-type charging device, storage-type charging system, and high-current chargeable lithium-ion battery

[0001] The present invention relates to a storage-type charging device, a storage-type charging system, and a large-current chargeable lithium-ion battery.

[0002] For example, Patent Document 1 discloses a charging system including an electric vehicle as an electric device and a charging device that charges a drive battery mounted on the electric vehicle. The charging device disclosed in Patent Document 1 includes a rectifier, a buffer secondary battery, and a DC-DC converter. The buffer secondary battery is a battery, such as a lithium-ion battery, built into the charging device. The charging device disclosed in Patent Document 1 is a storage-type charging device. In a first mode, power is taken in from a commercial AC power source via the rectifier and stored in the buffer secondary battery. In a second mode, the voltage output from the buffer secondary battery is boosted or reduced by a DC-DC converter depending on the voltage of, for example, a drive battery mounted on the vehicle, and then supplied to the drive battery.

[0003] For example, Patent Document 2 discloses a storage-type charging device having an internal battery. The battery to be charged by the storage-type charging device is charged via the internal battery. The storage-type charging device of Patent Document 2 does not have a DC-DC converter.

[0004] International Publication No. 2007 / 105612 Japanese Patent Application Laid-Open No. 2017-108556

[0005] There is a demand for storage-type charging devices that are simple in configuration and small in size, while shortening the charging time for high-current chargeable driving lithium-ion batteries that have a charging capacity sufficient to drive electrical devices.

[0006] The object of the present invention is to provide a storage-type charging device, a charging system, and a high-current rechargeable lithium-ion battery that can be made compact with a simple configuration and that can shorten the charging time of a high-current rechargeable lithium-ion battery that has a charging capacity sufficient to drive an electrical device.

[0007] In the charging system with a storage-type charging device disclosed in Patent Document 1, the storage-type charging device first charges an internal battery built into the storage-type charging device itself with power supplied from an external source. Next, the storage-type charging device supplies power from the internal battery to a drive battery mounted on an electrical device, charging the drive battery. When the drive battery discharges, the electrical device is driven by power output from the drive battery. The electrical device is, for example, an electric vehicle, and the drive battery has a large charging capacity sufficient to drive the electrical device.

[0008] The built-in battery of the storage-type charging device outputs direct current. The drive battery of the electrical device receives the direct current supply and is charged. The charging device in Patent Document 1 uses a DC-DC converter to boost or lower the voltage of the built-in battery before supplying power to the drive battery. This allows for adjustment of the charging state of the drive battery, which has a power capacity sufficient to drive an electric vehicle.

[0009] DC-DC converters typically control output voltage by repeatedly instantaneously storing and releasing power in a power retention element such as capacitance or inductance through rapid on-off switching of a switching element. Therefore, the current output by a DC-DC converter is limited by the electrical performance, thermal performance, and operating efficiency of the switching element and power retention element. For this reason, when power from the internal battery in Patent Document 1 is supplied to a driving battery, the current output from the internal battery may be limited to a small amount relative to the current the internal battery can output and the current the driving battery can accept.

[0010] In the storage-type charging device of Patent Document 2, the internal battery and the battery to be charged are connected without a DC-DC converter. More specifically, the storage-type charging device of Patent Document 2 measures the voltage difference between the internal battery and the battery to be charged, and if the voltage difference is equal to or less than an upper limit, it supplies current from the internal battery to the battery to be charged to charge it. The upper limit is a value set to prevent overcurrent, i.e., large current, from flowing to the battery to be charged. If the measured voltage difference is equal to or greater than the upper limit, the storage-type charging device of Patent Document 2 does not charge the battery using power from the internal battery and switches the charging current path to an AC-DC converter. In this way, the storage-type charging device of Patent Document 2 determines the charging state of the battery by measuring the voltage difference and attempts to suppress large currents in a path without a DC-DC converter. In the storage-type charging device of Patent Document 2, the connection path changes depending on the charging state of the battery to be charged. In other words, even when the same battery to be charged is connected, the connection path may change depending on the battery's state at the time of connection. Furthermore, the storage-type charging device of Patent Document 2 is required to measure the voltage difference between the internal battery and the battery being charged to prevent large currents from flowing. This complicates the structure of the storage-type charging device and the associated electrical device, even though the internal battery and the battery being charged may be connected without a DC-DC converter. Furthermore, charging time generally corresponds to the charge rate of the battery being charged at the start of charging. The charge rate can be said to be related to the amount of power that can be charged until the battery being charged is fully charged. Generally, the lower the charge rate at the start of charging, the longer the charging time. Additionally, in the storage-type charging device of Patent Document 2, if the charge rate of the battery being charged is lower than a certain upper limit, the charging current path switches to the AC-DC converter, significantly lengthening the charging time.

[0011] The inventors focused on the attributes of the battery itself, rather than the state of the battery, which varies from time to time. The inventors realized that by focusing on the attributes of the battery itself, it is possible to shorten the charging time by using a large current with a simple configuration.

[0012] More specifically, the inventors conceived a method for using a high-current rechargeable lithium-ion battery that satisfies the maximum operating voltage and high-current charging specifications as a battery for driving an electrical device, and a high-current dischargeable internal lithium-ion battery that satisfies the high-current discharge specifications as a battery built into a storage-type charging device. The inventors then conceived a method for detecting connection of a high-current rechargeable lithium-ion battery that satisfies the maximum operating voltage and high-current charging specifications to a charging device, and passing a large current through a high-current passing current output path without passing through a voltage converter so that the high-current rechargeable lithium-ion battery is charged with the large current output from the high-current dischargeable internal lithium-ion battery that satisfies the high-current discharge specifications. The high-current charging specification refers to a battery specification that allows charging at a rate of 10 C or higher for a charge capacity of 2.5 Ah. The high-current discharge specification refers to a battery specification that allows discharging at a rate of 10 C or higher for a charge capacity of 2.5 Ah. The high current refers to a current that corresponds to a charge rate of 10 C or higher for a charge capacity of 2.5 Ah.

[0013] In a high-current rechargeable driving lithium-ion battery having the above attributes, the high-current passable current output path from the high-current dischargeable built-in lithium-ion battery does not include a voltage converter, so current is not restricted by a voltage converter. Furthermore, situations such as occasional changes in the charging path, which would otherwise lengthen the charging time, are suppressed. When the high-current rechargeable driving lithium-ion battery is charged at a charge rate of 10 C or higher using power stored in the high-current dischargeable built-in lithium-ion battery, for example, half of the full charge amount can be charged in approximately three minutes or less. Therefore, a high-current rechargeable driving lithium-ion battery with a charge capacity of 2.5 Ah or more, which is sufficient to power an electrical device, can be charged in a short time.

[0014] The charging system according to each aspect of the present invention, which has been completed based on the above findings, has the following configuration.

[0015] (1) A storage-type charging device that has a large-current rechargeable driving lithium-ion battery mounted thereon and is detachably connected to an electrical device driven by the power of the large-current rechargeable driving lithium-ion battery to charge the large-current rechargeable driving lithium-ion battery, the storage-type charging device comprising: a charging object connection part that electrically connects with the large-current rechargeable driving lithium-ion battery; a large-current dischargeable built-in lithium-ion battery that is provided in the storage-type charging device and is charged with power supplied from a power source external to the storage-type charging device and external to the electrical device, and that satisfies large-current discharge specifications; and a large-current passing current output path that connects the large-current dischargeable built-in lithium-ion battery and the charging object connection part without passing through a voltage converter, and is characterized as follows: the storage-type charging device, a compatible battery detection and switch unit that is provided in the large-current passing current output path and that, upon detecting that the large-current rechargeable driven lithium-ion battery that satisfies maximum voltage specifications during use and large-current charging specifications has been connected to the charging target connection unit and turning on, passes the large current to the large-current passing current output path without passing through the voltage converter so that the large-current rechargeable driven lithium-ion battery is charged with the large current output from the large-current dischargeable built-in lithium-ion battery; the storage-type charging device is configured not to have a function for switching the path through which the large current passes from the large-current passing current output path to another path during charging with the large current, depending on the potential difference between the large-current rechargeable driven lithium-ion battery and the large-current dischargeable built-in lithium-ion battery; the large-current discharge specification means a battery specification that allows for discharging at a maximum current during use corresponding to a rate of 10 C or more for a charge capacity of 2.5 Ah; and the large-current charge specification means a battery specification that allows for charging at a maximum current during use corresponding to a rate of 10 C or more for a charge capacity of 2.5 Ah. The large current is a current corresponding to a rate of 10 C or more for a charge capacity of 2.5 Ah.

[0016] According to the configuration (1), the compatible battery detection / switch unit detects the connection of a high-current rechargeable drive lithium-ion battery that meets the maximum voltage specification during use and the high-current charging specification and turns on. This allows a high current to pass through the high-current passing current output path without passing through a voltage converter. As a result, the high-current rechargeable drive lithium-ion battery that meets the high-current charging specification is charged by the high current output from the high-current dischargeable built-in lithium-ion battery that meets the high-current discharge specification. The high-current charging specification allows for discharge at a maximum current during use corresponding to a rate of 10C or higher for a charge capacity of 2.5 Ah. The high-current discharge specification allows for discharge at a maximum current during use corresponding to a rate of 10C or higher for a charge capacity of 2.5 Ah. The high current is a current corresponding to a rate of 10C or higher for a charge capacity of 2.5 Ah.

[0017] The compatible battery detection and switch unit does not switch the high-current passing current output path to a path other than the high-current passing current output path depending on the potential difference between the high-current rechargeable drive lithium-ion battery and the high-current dischargeable internal lithium-ion battery, but turns on when it detects the connection of a high-current rechargeable drive lithium-ion battery that meets the maximum operating voltage specification and high-current charging specification. In other words, the compatible battery detection and switch unit does not switch paths depending on, for example, the measurement results of the state of the high-current rechargeable drive lithium-ion battery, but instead charges the battery via the high-current passing current output path by identifying the attributes of the high-current rechargeable drive lithium-ion battery. When charging a high-current rechargeable drive lithium-ion battery that meets the maximum operating voltage specification and high-current charging specification, the high-current passing current output path from the high-current dischargeable internal lithium-ion battery does not include a voltage converter. Therefore, when it is identified that a high-current rechargeable drive lithium-ion battery is connected, a large current flows from the high-current dischargeable internal lithium-ion battery to the high-current rechargeable drive lithium-ion battery. Specifically, the high-current rechargeable driving lithium-ion battery is charged at a charge rate of 10 C or higher using power stored in the high-current dischargeable internal lithium-ion battery. Furthermore, the high-current passing current output path is turned on based on the specifications of the connected high-current rechargeable driving lithium-ion battery, and is not switched based on the charging state, which changes over time. This prevents the magnitude of the charging current from changing due to path switching over time. This reduces fluctuations in charging time depending on the charging state. This prevents excessively long charging times depending on the charging state. This allows a high-current rechargeable driving lithium-ion battery with a charging capacity of 2.5 Ah or more, which can power an electrical device, to be charged in a short time. Thus, with the configuration (1), a large-current spontaneous charging can be performed from the large-current dischargeable internal lithium-ion battery via the large-current passing current output path to the high-current rechargeable driving lithium-ion battery, shortening the charging time. This large-current spontaneous charging can be performed by leaving both batteries to their own devices. With high current, random charging, there are no current limitations imposed by a voltage converter.In large-current spontaneous charging, there is a positive correlation between the magnitude of the potential difference between the large-current dischargeable built-in lithium-ion battery and the large-current rechargeable driving lithium-ion battery and the magnitude of the charging current reaching the large-current rechargeable driving lithium-ion battery via the large-current passing current output path. In large-current spontaneous charging, the charging current decreases as the potential difference decreases. Large-current spontaneous charging can be performed in a manner in which neither the voltage value nor the current value is controlled. The configuration (1) allows large-current spontaneous charging without changing the path. Thus, the configuration (1) allows the storage-type charging device to be compact with a simple configuration and shortens the charging time for a large-current rechargeable driving lithium-ion battery with a charging capacity sufficient to drive an electrical device.

[0018] (2) The storage-type charging device of (1), wherein the storage-type charging device detects that the large-current rechargeable driven lithium-ion battery that satisfies the maximum voltage specification during use and the large-current charging specification has been connected to the charging object connection part by detecting that the charging object connection part has been mechanically connected to the large-current rechargeable driven lithium-ion battery or the electrical device, or by communicating with the electrical device and acquiring information representing the attributes of the large-current rechargeable driven lithium-ion battery.

[0019] According to the above configuration, it is possible to detect with a simple configuration that a large current chargeable driving lithium ion battery has been connected to a charging object connection part.

[0020] (3) The storage-type charging device according to (1) or (2), wherein the large-current dischargeable built-in lithium-ion battery has a negative electrode containing at least one selected from the group consisting of spinel-type lithium titanate, niobium-titanium-containing composite oxide, and graphite.

[0021] According to the above configuration, the negative electrode of the large-current dischargeable built-in lithium-ion battery contains at least one selected from the group consisting of spinel-type lithium titanate, niobium-titanium-containing composite oxide, and graphite. A negative electrode containing at least one selected from the group consisting of spinel-type lithium titanate, niobium-titanium-containing composite oxide, and graphite can reduce the possibility of an internal short circuit occurring due to lithium precipitation in the negative electrode. A large-current dischargeable built-in lithium-ion battery having such a negative electrode can suppress a shortened lifespan even when outputting a maximum discharge current during use that is equal to or greater than the current equivalent to a 10C charge rate for a large-current rechargeable drive lithium-ion battery. Therefore, the large-current rechargeable drive lithium-ion battery can be charged in a short time while suppressing a shortened lifespan.

[0022] (4) The storage-type charging device according to any one of (1) to (3), wherein the large-current chargeable driving lithium-ion battery has a negative electrode containing at least one selected from the group consisting of spinel-type lithium titanate, niobium-titanium-containing composite oxide, and graphite.

[0023] According to the above configuration, the high-current rechargeable driving lithium-ion battery can suppress shortening of its lifespan even when charged at a maximum discharge current during use equal to or greater than the current equivalent to a 10C charge rate. Therefore, the high-current rechargeable driving lithium-ion battery can be charged in a short time while suppressing shortening of its lifespan. Furthermore, for example, if the high-current dischargeable internal lithium-ion battery and the high-current rechargeable driving lithium-ion battery share a common positive electrode material and a common negative electrode material, the high-current dischargeable internal lithium-ion battery and the high-current rechargeable driving lithium-ion battery used in the charging system can be constructed from common cells. This makes it easier to manage the lithium-ion batteries.

[0024] (5) The storage-type charging device according to any one of (1) to (4), further comprising a pre-charging unit that charges the large-current dischargeable built-in lithium-ion battery at a voltage equal to or lower than the maximum charging voltage of the large-current dischargeable built-in lithium-ion battery using power supplied from a power source external to the storage-type charging device and the electrical device.

[0025] The pre-charging unit charges the large-current dischargeable internal lithium-ion battery prior to discharging the large-current dischargeable internal lithium-ion battery. According to the above configuration, the large-current dischargeable internal lithium-ion battery is charged at a voltage equal to or lower than its maximum charging voltage. The charged large-current dischargeable internal lithium-ion battery outputs a voltage lower than the voltage applied during charging. Therefore, the charging voltage of the large-current rechargeable driving lithium-ion battery can be set to or lower than its maximum charging voltage without providing a voltage converter in the large-current passing current output path. Therefore, the large-current rechargeable driving lithium-ion battery can be charged in a short time while maintaining the charging voltage of the large-current rechargeable driving lithium-ion battery below its maximum charging voltage. The pre-charging unit is, for example, built into the housing of the storage-type charging device. However, the pre-charging unit is not particularly limited and may be a so-called AC adapter installed outside the housing of the storage-type charging device. The "external power source of the storage-type charging device and the electrical device" refers, for example, to a power source not included in either the storage-type charging device or the electrical device. The power source is not particularly limited. An example of the power source is a commercial power source. The commercial power source is, for example, a commercial AC power source.

[0026] (6) A charging system comprising: a storage-type charging device according to any one of (1) to (5); and an electric device connected to the storage-type charging device and driven by the power of the high-current rechargeable driving lithium-ion battery charged by the storage-type charging device.

[0027] According to the above configuration, the storage-type charging device of the charging system can be made compact with a simple configuration, and the charging time of the large current chargeable lithium ion battery can be shortened.

[0028] (7) The large-current rechargeable driving lithium-ion battery is mounted on the electric device of the charging system of (6) and is charged by the storage-type charging device.

[0029] According to the above configuration, the large current chargeable lithium ion battery can be made smaller with a simple configuration, and the charging time of the large current chargeable lithium ion battery can be shortened.

[0030] The terminology used herein is for the purpose of defining particular embodiments only and is not intended to limit the invention. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed components. As used herein, the use of the terms "including," "comprising," or "having," and variations thereof, identifies the presence of stated features, steps, operations, elements, components, and / or equivalents thereof, but may include one or more of the steps, operations, elements, components, and / or groups thereof. As used herein, the terms "attached," "coupled," and / or equivalents thereof are used broadly and encompass both 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 ordinary skill in the art to which this invention belongs. Terms, such as commonly used dictionary-defined terms, should be interpreted to have a meaning consistent with the meaning in the relevant art and in the context of this disclosure, and should not be interpreted in an idealized or overly formal sense unless explicitly defined herein. It will be understood that numerous techniques and steps are disclosed in the description of the present invention. Each of these has distinct advantages, and each can be used with one or more, or in some cases all, of the other disclosed techniques. Therefore, for the sake of clarity, this description will refrain from unnecessarily repeating every possible combination of the individual steps. Nevertheless, the specification and claims should be read with the understanding that all such combinations are within the scope of the present invention. A novel storage-type charging device is described herein. In the following description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.The present disclosure is to be considered as an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated by the following drawings or description.

[0031] A storage-type charging device is a device that charges an electrical device. A storage-type charging device is a charging device that can charge itself. A storage-type charging device is, for example, smaller and lighter than an electrical device. A portable charging device is, for example, a portable charging device that is configured to move on the ground by being pushed or pulled by a person. A storage-type charging device may be configured to be portable. A storage-type charging device is, for example, a portable charging device. In the case of a portable charging device, for example, the electrical device can be charged even if the electrical device is located far from a commercial power source. However, the storage-type charging device is not particularly limited and may, for example, be larger than the electrical device. Furthermore, a storage-type charging device may be a stationary device or a building.

[0032] An electric device is a device that runs on electricity. An example of an electric device is a vehicle, i.e., an EV (Electric Vehicle). An EV may be a BEV (Battery-powered Electric Vehicle) or an HEV (Hybrid Electric Vehicle) having an internal combustion engine. An electric device may be, for example, a PHEV (Plug-in Hybrid Electric Vehicle). When the electric device is a vehicle, it can be charged, for example, at a destination that is far from a commercial power source. An example of a type of vehicle is an electric straddle-type vehicle. A straddle-type vehicle is a vehicle in which the driver sits astride a saddle. Examples of electric straddle-type vehicles include electric two-wheelers and electric three-wheelers. In an electric saddle-ride type vehicle, posture control is performed by the rider's weight shift when the driver is riding or turning. The vehicle body of a saddle-ride type vehicle is preferably lightweight and compact so that posture control can be smoothly performed by the rider's weight shift. Therefore, the installation space for a high-current rechargeable drive lithium-ion battery in a saddle-ride type vehicle is generally severely limited. Furthermore, an electric saddle-ride type vehicle may include a bicycle that can be driven by pedaling force, or it may not include such a bicycle. The electric device included in the bicycle here may be configured to output a driving force sufficient to drive the bicycle without pedaling force, or may be configured to output a driving force to assist pedaling force. In addition, the vehicle is not limited to the above examples and may be an electric car, electric truck, electric bus, electric ship, electric drone, or electric aircraft. Furthermore, the electric device is not particularly limited and may be a device that does not move when in operation, such as a pump device, an electric oven, or a machine tool.

[0033] High-current rechargeable drive lithium-ion batteries and high-current dischargeable built-in lithium-ion batteries are lithium-ion batteries. Lithium-ion batteries are batteries that can be charged and discharged. Lithium-ion batteries are secondary batteries that charge and discharge through chemical reactions at the electrodes. Lithium-ion batteries charge and discharge through oxidation and reduction reactions at the electrodes. Lithium-ion batteries convert stored chemical energy into electrical energy. The terminal voltage of a lithium-ion battery is not proportional to the amount of power stored in the battery. For example, lithium-ion capacitors are not included in the category of lithium-ion batteries. Lithium-ion batteries contain lithium oxide in the positive electrode. Lithium batteries that use lithium metal in the positive electrode are not included in the category of lithium-ion batteries. Lithium-ion batteries are non-aqueous lithium-ion batteries that use a non-aqueous electrolyte, such as an organic solvent.

[0034] A battery meeting the high-current charging specification means that the battery can be charged at the current specified by the high-current charging specification. A battery meeting the high-current discharging specification means that the battery can be discharged at the current specified by the high-current discharging specification. A battery meeting the maximum operating voltage specification means that the battery can operate at a voltage equal to or lower than the voltage specified by the maximum operating voltage specification. Meeting the maximum operating voltage specification means, for example, that the maximum voltage of the battery during use is equal to or higher than the voltage applied to the battery from an external source. More specifically, a high-current rechargeable lithium-ion battery meeting the maximum operating voltage specification means, for example, that the maximum voltage of the high-current rechargeable lithium-ion battery during use is equal to or higher than the maximum discharge voltage of a high-current dischargeable internal lithium-ion battery connected to the high-current rechargeable lithium-ion battery via a high-current passable current output path that does not involve a voltage converter.

[0035] The high-current charging specification is set so as not to change in response to the state or changes in the state of the high-current rechargeable lithium-ion battery. The high-current charging specification is set so as not to change in response to the state or changes in the state of the high-current rechargeable lithium-ion battery. The high-current charging specification is also set so as not to change in response to the state or changes in the state of the high-current dischargeable built-in lithium-ion battery. The high-current discharging specification is set so as not to change in response to the state or changes in the state of the high-current dischargeable built-in lithium-ion battery. The high-current charging specification current (maximum chargeable current during use) is sometimes referred to as the rated charging current. The high-current discharging specification current (maximum dischargeable current during use) is sometimes referred to as the rated discharge current. The current of the high-current charging specification and the current of the high-current discharging specification are both fixed values, for example. The high-current charging specification and the high-current discharging specification can be set by selecting the performance of the batteries that make up the high-current dischargeable built-in lithium-ion battery and the high-current rechargeable lithium-ion battery.

[0036] The maximum operating voltage specification of a high-current rechargeable lithium-ion battery is set so as not to change depending on the state or changes in the state of the high-current rechargeable lithium-ion battery. The maximum operating voltage specification is also set so as not to change depending on the state or changes in the state of a high-current dischargeable internal lithium-ion battery. The maximum operating voltage specification indicates the maximum voltage that can be applied to the battery. The maximum operating voltage specification is set, for example, during the design and manufacture of the battery. The maximum operating voltage specification is determined, for example, depending on the number of battery cells and the type of electrodes of the battery cells. The maximum operating voltage specification is set, for example, as a fixed value.

[0037] The capacity or charge capacity of a battery is the amount of charge that can be stored in the battery. It is measured in Ah. The charge capacity of a battery is equal to its discharge capacity. Discharge capacity is the cumulative amount of current output over time, from the time a fully charged battery starts outputting current along with an initial voltage until the output voltage reaches its final voltage. The discharge condition is, for example, discharging a current that reaches the final voltage in 10 hours (10-hour rate). The large-current dischargeable built-in lithium-ion battery and the large-current rechargeable drive lithium-ion battery are each composed of, for example, lithium-ion battery cells connected in series. Therefore, the discharge voltage, which is a condition for discharge capacity, varies depending on the number of lithium-ion battery cells in the lithium-ion battery. However, the discharge capacity is determined regardless of the number of lithium-ion battery cells.

[0038] The rate of a battery represents the speed at which charge is accumulated or released. It is measured in C. The high-current charging specification corresponds to the maximum charge rate allowed when charging. The current corresponding to the maximum charge rate is the maximum usage current. The current magnitude that fully charges the battery's capacity in one hour is defined as 1 C. For example, if the battery capacity is 2.5 Ah, 1 C is 2.5 A. A high-current rechargeable lithium-ion battery that meets the high-current charging specification for a charge rate of 10 C or more is charged, for example, with a charging current equal to or greater than the current equivalent to 10 C and equal to or less than the current specified for the high-current charging specification. The high-current charging specification corresponds to the maximum discharge rate allowed when discharging. The current value corresponding to the maximum discharge rate is the current specified for the high-current charging specification.

[0039] The high-current dischargeable built-in lithium-ion battery has a charge capacity of 2.5 Ah or more, which is a prerequisite for meeting the high-current discharge specification. The high-current rechargeable drive lithium-ion battery has a charge capacity of 2.5 Ah or more, which is a prerequisite for meeting the high-current charge specification. For example, a high-current dischargeable built-in lithium-ion battery or a high-current rechargeable drive lithium-ion battery with a charge capacity of 2.5 Ah or more is smaller than a device that charges electrical physical energy, such as a capacitor. By having a charge capacity of 2.5 Ah or more, the high-current rechargeable drive lithium-ion battery can charge or discharge power consumed for mechanical operation of an electrical device, rather than simply power for information processing or information presentation in the electrical device. For example, if a high-current rechargeable drive lithium-ion battery has an output voltage of 12 V and a charge capacity of 2.5 Ah, outputting a 50 A current for 20 seconds corresponds to a power consumption of approximately 10%. This consumption enables approximately 600 W, or simply, approximately 0.8 ps of drive for 20 seconds. A charge capacity of 2.5 Ah or more is a capacity that allows for at least five consecutive 20-second runs without charging, using 50% of the charge capacity.

[0040] The charging object connection part is, for example, a charging cable extending from the housing of the storage-type charging device to the outside and a connector provided at the tip of the charging cable. However, the charging object connection part is not particularly limited and may be, for example, a connector provided in the housing of the storage-type charging device and configured to connect to the charging cable.

[0041] The compatible battery detection and switch unit may include, for example, a semiconductor element, but is not limited to this and may also be, for example, a component such as a relay that mechanically passes or cuts off current.

[0042] When an object is configured not to have a certain function, it means that the object does not have that function. The storage-type charging device is configured not to have the function of switching the path through which the large current passes from the large-current passing current output path to another path in accordance with the potential difference between the large-current rechargeable driving lithium-ion battery and the large-current dischargeable built-in lithium-ion battery during high-current charging. For example, the compatible battery detection and switch unit included in the storage-type charging device does not have the function of switching the path through which the large current passes from the large-current passing current output path to another path in accordance with the potential difference between the large-current rechargeable driving lithium-ion battery and the large-current dischargeable built-in lithium-ion battery during high-current charging. When the compatible battery detection and switch unit detects that a large-current rechargeable driving lithium-ion battery that meets the maximum operating voltage specifications and the large-current charging specifications has been connected to the charging target connection unit, it turns on and passes the large current to the large-current passing current output path without passing through the voltage converter.

[0043] The current output path allowing large current to pass is connected via an output switch unit without going through a voltage converter. The voltage converter is a circuit device that converts an input voltage. The voltage converter converts the input voltage, for example, by quickly switching the on / off state of a switching element. The current output path allowing large current to pass may include electrical components other than the voltage converter or the output switch unit. The current output path allowing large current to pass may include, for example, one or a combination of wiring, a fuse, a connector, and a resistor for current measurement.

[0044] The information representing the attributes of the high-current rechargeable lithium-ion battery is information that directly or indirectly corresponds to the maximum voltage specification and high-current charging specification of the high-current rechargeable lithium-ion battery. For example, the information representing the attributes may be the model number of the high-current rechargeable lithium-ion battery, and the model number corresponds to the maximum voltage specification and high-current charging specification. However, the information representing the attributes is not particularly limited and may also indicate the class of the maximum voltage specification and high-current charging specification of the high-current rechargeable lithium-ion battery.

[0045] According to the present invention, it is possible to reduce the size of the storage-type charging device with a simple configuration, while shortening the charging time of a large-current chargeable driving lithium-ion battery having a charging capacity sufficient to drive an electrical device.

[0046] Fig. 1 is a block diagram showing the schematic configuration of a charging system having an electric storage type charging device according to a first embodiment. Fig. 1(a) is a diagram showing an example of the configuration of a driving lithium ion battery shown in Fig. 1. Fig. 1(b) is a diagram showing an example of the configuration of an internal lithium ion battery shown in Fig. 1. Fig. 1(c) is a chart showing the maximum current of a driving lithium ion battery and an internal lithium ion battery. Fig. 1 is a diagram explaining an application example of the electric storage type charging device and charging system shown in Fig. 1. Fig. 1 is a block diagram showing the schematic configuration of an electric storage type charging device according to a second embodiment.

[0047] Hereinafter, embodiments will be described with reference to the drawings.

[0048] First Embodiment FIG. 1 is a block diagram showing a schematic configuration of a charging system including an electricity storage type charging device according to a first embodiment.

[0049] The power storage type charging device 1 shown in Fig. 1 is provided in a charging system A. The charging system A includes the power storage type charging device 1 and an electric device 2. The power storage type charging device 1 is a device that charges the electric device 2. First, an object that is charged by the power storage type charging device 1 will be described.

[0050] [Electrical Device] The electrical device 2 is equipped with a high-current rechargeable driving lithium-ion battery 22. The electrical device 2 is driven by power from the high-current rechargeable driving lithium-ion battery 22. The electrical device 2 includes a driving device 25. The driving device 25 operates by receiving power from the high-current rechargeable driving lithium-ion battery 22. The driving device 25 drives the electrical device 2 by power from the high-current rechargeable driving lithium-ion battery 22. The electrical device 2 has a charging connector 21. Power is supplied to the driving lithium-ion battery 22 from the storage-type charging device 1 via the charging connector 21.

[0051] [Drive Lithium-ion Battery] The drive lithium-ion battery 22 stores power for driving the electric device 2. The drive lithium-ion battery 22 is a rechargeable secondary battery. The drive lithium-ion battery 22 has a charge capacity of 2.5 Ah or more. Therefore, the drive lithium-ion battery 22 can store power for driving the electric device 2.

[0052] The high-current chargeable driving lithium-ion battery 22 satisfies the maximum usage voltage specification and the high-current charging specification. The high-current charging specification means that the battery can be charged at a maximum usage current corresponding to a rate of 10 C or more for a charging capacity of 2.5 Ah. The maximum usage current during charging is also referred to as the maximum charging current. The high current is a current corresponding to a rate of 10 C or more for a charging capacity of 2.5 Ah. Hereinafter, in this specification, the high-current chargeable driving lithium-ion battery 22 will be simply referred to as the driving lithium-ion battery 22. The maximum usage current during charging will also be referred to as the maximum charging current.

[0053] The driving lithium-ion battery 22 has a maximum charge voltage and a maximum discharge voltage. The maximum charge voltage is the maximum voltage that can be applied to the driving lithium-ion battery 22 when charging the driving lithium-ion battery 22. The maximum discharge voltage is the maximum voltage that can be output when the driving lithium-ion battery 22 is discharging. The voltage output when the driving lithium-ion battery 22 is discharging is lower than the voltage applied when the driving lithium-ion battery 22 is charging. Therefore, the maximum discharge voltage is lower than the maximum charge voltage. The maximum charge voltage is higher than the maximum discharge voltage. The maximum usage voltage specification of the driving lithium-ion battery 22 indicates the maximum voltage when the driving lithium-ion battery 22 is in use. The maximum usage voltage specification of the driving lithium-ion battery 22 indicates the maximum charging voltage of the driving lithium-ion battery 22.

[0054] The maximum charging voltage indicated by the maximum usage voltage specification of the driving lithium-ion battery 22 indicates the maximum voltage that can be applied when charging the driving lithium-ion battery 22. Hereinafter, the maximum usage voltage specification of the driving lithium-ion battery 22 is also referred to as the maximum charging voltage of the driving lithium-ion battery 22. The maximum charging voltage of the driving lithium-ion battery 22 is set according to the operating specifications of the electric device 2 during the design and manufacture of the driving lithium-ion battery 22. The set value of the maximum charging voltage of the driving lithium-ion battery 22 can be set, for example, based on the number of cells constituting the driving lithium-ion battery 22. The range in which the maximum charging voltage of the driving lithium-ion battery 22 is set is, for example, 12 V or higher and 72 V or lower. For example, when the maximum charging voltage of the driving lithium-ion battery 22 is set to a value of 12 V or higher, it is easier to obtain the current required to rapidly charge the electric power required to drive the electric device 2 compared to when the maximum charging voltage is limited to, for example, less than 12 V. When the maximum charging voltage of the driving lithium-ion battery 22 is set to a value of, for example, 24 V or higher, the amount of current required to supply a specific electric power can be reduced compared to when the maximum charging voltage is less than 24 V. Furthermore, when the maximum charging voltage of the driving lithium-ion battery 22 is, for example, 72 V or less, the electrical insulation structures of the storage-type charging device 1 and the electrical device 2 can be simplified and made smaller than when the maximum charging voltage exceeds, for example, 72 V. Furthermore, when the maximum charging voltage of the driving lithium-ion battery 22 is, for example, less than 60 V, it operates within the range of "extra low voltage (ELV)" or "safety extra low voltage (SELV)" defined in the IEC 60950 standard of the International Electrotechnical Commission (IEC). Therefore, the insulation structure is simpler and can be made smaller than when the maximum charging voltage is 60 V or more.

[0055] The electrical device 2 shown in FIG. 1 includes a battery identification unit 26. The battery identification unit 26 causes the storage-type charging device 1 to detect that a driving lithium-ion battery 22 that meets the maximum operating voltage specification and the large-current charging specification has been connected. The battery identification unit 26 identifies, for example, the attributes of the driving lithium-ion battery 22. The battery identification unit 26 stores identification information that indicates the attributes of the driving lithium-ion battery 22, such as the type of the driving lithium-ion battery 22. The battery identification unit 26 outputs the identification information to an external device electrically connected to it. The battery identification unit 26 shown in FIG. 1 is built into the driving lithium-ion battery 22. However, the location of the battery identification unit 26 is not particularly limited, and it may be provided external to the driving lithium-ion battery 22, for example.

[0056] [Storage-type charging device] The storage-type charging device 1 is a charging device that is detachably connected to an electric device 2. When connected to the electric device 2, the storage-type charging device 1 charges the driving lithium-ion battery 22 of the electric device 2. The storage-type charging device 1 comprises a charging target connection section 11, a built-in lithium-ion battery 12 capable of discharging a large current, a compatible battery detection and switch section 13, and a current output path 14 that allows a large current to pass through.

[0057] The charge target connection unit 11 is electrically and detachably connected to the driving lithium-ion battery 22. The charge target connection unit 11 has a charge cable 11a and an output connector 11b. The charge cable 11a extends from the housing 16 of the storage type charging device 1 to the outside. The output connector 11b is provided on the charge cable 11a. The output connector 11b is mechanically and electrically connected to the charge connector 21 of the electrical device 2 in a detachable manner. With the charge target connection unit 11 electrically connected to the driving lithium-ion battery 22, power is supplied from the built-in lithium-ion battery 12 of the storage type charging device 1 to the driving lithium-ion battery 22 of the electrical device 2.

[0058] [Large-Current Dischargeable Built-in Lithium-ion Battery] Large-current dischargeable built-in lithium-ion battery 12 is charged with power supplied from power source C external to storage-type charging device 1 and external to electrical device 2. Large-current dischargeable built-in lithium-ion battery 12 charges driving lithium-ion battery 22 of electrical device 2 with the power stored in large-current dischargeable built-in lithium-ion battery 12. Large-current dischargeable built-in lithium-ion battery 12 is a rechargeable secondary battery. Large-current dischargeable built-in lithium-ion battery 12 has a charge capacity of 2.5 Ah or more. Therefore, large-current dischargeable built-in lithium-ion battery 12 can fully charge driving lithium-ion battery 22 with a single charge.

[0059] The built-in lithium-ion battery 12 capable of high-current discharge meets the high-current discharge specification. The high-current discharge specification refers to a battery specification that allows discharge at a maximum current during use equivalent to a rate of 10 C or more for a charge capacity of 2.5 Ah. The high current is a current equivalent to a rate of 10 C or more for a charge capacity of 2.5 Ah. Hereinafter, in this specification, the built-in lithium-ion battery 12 capable of high-current discharge will also be simply referred to as the built-in lithium-ion battery 12.

[0060] The built-in lithium-ion battery 12 has a maximum charge voltage and a maximum discharge voltage. The maximum charge voltage is the maximum voltage that can be applied to the built-in lithium-ion battery 12 when charging it. The maximum discharge voltage is the maximum voltage that can be output when the built-in lithium-ion battery 12 is discharging. The voltage output by the driving lithium-ion battery 22 when discharging is lower than the voltage applied when the built-in lithium-ion battery 12 is charging. Therefore, the maximum discharge voltage is lower than the maximum charge voltage. The maximum charge voltage is higher than the maximum discharge voltage. The maximum voltage specification for the built-in lithium-ion battery 12 during use indicates the maximum voltage when the built-in lithium-ion battery 12 is in use. The maximum voltage specification for the built-in lithium-ion battery 12 during use indicates the maximum charge voltage of the built-in lithium-ion battery 12.

[0061] The maximum charging voltage indicated by the maximum voltage specification for the internal lithium-ion battery 12 during use is set during the design and manufacture of the internal lithium-ion battery 12 according to the operating specifications and charging speed requirements of the electrical device 2. The maximum charging voltage for the internal lithium-ion battery 12 can be set based on the number of cells constituting the internal lithium-ion battery 12. Hereinafter, the maximum voltage specification for the internal lithium-ion battery 12 during use is also referred to as the maximum charging voltage of the internal lithium-ion battery 12. The maximum charging voltage for the internal lithium-ion battery 12 can be set within a range of, for example, 12 V to 72 V. For example, when the maximum charging voltage of the driving lithium-ion battery 22 is set to a value of 12 V or higher, it is easier to obtain the current required to rapidly charge the electrical device 2 with the power required to drive the electrical device 2, compared to when the maximum charging voltage is limited to, for example, less than 12 V. When the maximum charging voltage of the driving lithium-ion battery 22 is set to a value of, for example, 24 V or higher, it is possible to reduce the amount of current required to supply a specific amount of power, compared to when the maximum charging voltage is less than 24 V. Furthermore, when the maximum charging voltage of the driving lithium-ion battery 22 is, for example, 72 V or less, the electrical insulation structures of the storage-type charging device 1 and the electrical device 2 can be simplified and made smaller than when the maximum charging voltage exceeds, for example, 72 V. Furthermore, when the maximum charging voltage of the driving lithium-ion battery 22 is, for example, less than 60 V, it operates within the "extra low voltage" (ELV or safety extra low voltage) range defined in the IEC 60950 standard of the International Electrotechnical Commission (IEC). Therefore, the insulation structure can be simplified and made smaller than when the maximum charging voltage is 60 V or more.

[0062] [Current output path allowing large current to pass] Current output path 14 outputs current from storage type charging device 1. Current output path 14 is a current path that connects built-in lithium ion battery 12 and charging object connection part 11 without going through a voltage converter. Hereinafter in this specification, current output path 14 allowing large current to pass will be simply referred to as current output path 14. Current output path 14 allowing large current to pass can pass a large current by connecting built-in lithium ion battery 12 and charging object connection part 11 without going through a voltage converter.

[0063] [Compatible Battery Detection and Switch Unit] The compatible battery detection and switch unit 13 is provided in the current output path 14. The compatible battery detection and switch unit 13 controls the supply or cut-off of current output from the built-in lithium-ion battery 12. The compatible battery detection and switch unit 13 turns on when it detects that a driving lithium-ion battery 22 that meets the maximum operating voltage specifications and large current charging specifications has been connected to the charging object connection unit 11. The compatible battery detection and switch unit 13 does not turn on if it does not detect that a driving lithium-ion battery 22 that meets the maximum operating voltage specifications and large current charging specifications has been connected to the charging object connection unit 11.

[0064] The compatible battery detection and switch unit 13 is turned on to electrically connect the built-in lithium-ion battery 12 and the charging target connector 11, or turned off to electrically disconnect them. The compatible battery detection and switch unit 13 includes, for example, a semiconductor element.

[0065] For example, when electrically connected to the battery identification unit 26 of the electrical device 2, the compatible battery detection and switch unit 13 communicates with the battery identification unit 26 and acquires information indicating the attributes of the driving lithium-ion battery 22 from the battery identification unit 26. If the identification based on the acquired attributes of the driving lithium-ion battery 22 indicates that the driving lithium-ion battery 22 satisfies the maximum operating voltage specification and the large-current charging specification, the compatible battery detection and switch unit 13 turns on and passes current. For example, the compatible battery detection and switch unit 13 determines that the maximum operating voltage specification is that the maximum charging voltage of the driving lithium-ion battery 22 is equal to or greater than the maximum discharge voltage of the internal lithium-ion battery 12 connected to the driving lithium-ion battery 22 via the current output path 14. For example, the compatible battery detection and switch unit 13 determines that the large-current charging specification is that the driving lithium-ion battery 22 can be charged at the maximum operating current. As a result, the large current output from the built-in lithium-ion battery 12 passes through the current output path 14 without passing through the voltage converter, so that the driving lithium-ion battery 22 is charged by the large current output from the built-in lithium-ion battery 12.

[0066] The storage battery charging device 1 is configured not to have the function of switching the path through which the large current passes from the current output path 14 to another path in response to the potential difference between the driving lithium-ion battery 22 and the built-in lithium-ion battery 12 during charging with a large current. The compatible battery detection and switch unit 13 does not switch the current output path 14 to any path other than the current output path 14 in response to the potential difference between the driving lithium-ion battery 22 and the built-in lithium-ion battery 12. The compatible battery detection and switch unit 13 turns on when it detects that a driving lithium-ion battery 22 that meets the maximum operating voltage specifications and large-current charging specifications has been connected. In other words, the compatible battery detection and switch unit 13 does not switch paths in response to the measurement results of the driving lithium-ion battery 22's status, but rather charges via the current output path 14 by identifying the attributes of the driving lithium-ion battery 22.

[0067] In this way, when a driving lithium-ion battery 22 that meets the large current charging specifications is connected to the charging target connection unit 11, current flows from the built-in lithium-ion battery 12 to the driving lithium-ion battery 22 via the compatible battery detection / switch unit 13.

[0068] More specifically, the driving lithium-ion battery 22 can be charged at a maximum current during use corresponding to a rate of 10 C or more for a charge capacity of 2.5 Ah or more. In contrast, the built-in lithium-ion battery 12 can be discharged at a maximum current during use corresponding to a rate of 10 C or more for a charge capacity of 2.5 Ah or more. Furthermore, the current output path 14 can pass a large current corresponding to a rate of 10 C or more for a charge capacity of 2.5 Ah.

[0069] The compatible battery detection and switch unit 13 does not switch paths based on the measurement results of the driving lithium-ion battery 22 status, but rather identifies the attributes of the driving lithium-ion battery 22 and charges it through the current output path 14. When charging a driving lithium-ion battery 22 that meets the maximum operating voltage and high-current charging specifications, the current output path 14 through which current flows from the internal lithium-ion battery 12 does not include a voltage converter. Therefore, when the connected driving lithium-ion battery 22 is identified, a large current flows from the internal lithium-ion battery 12 to the driving lithium-ion battery 22. Specifically, the driving lithium-ion battery 22 is charged at a charge rate of 10 C or higher using power stored in the internal lithium-ion battery 12. Furthermore, the current output path 14 is turned on based on the specifications of the connected driving lithium-ion battery 22, not based on the charging state, which changes over time. This prevents changes in the magnitude of the charging current due to path switching depending on the charging state. This prevents drastic reductions in charging time due to the charging state. In other words, the charging time is prevented from becoming extremely long due to different charging states depending on the battery. Therefore, the driving lithium-ion battery 22 having a charge capacity of 2.5 Ah or more, which is sufficient to drive the electric device 2, is charged in a short time. The storage-type charging device 1 can be made compact with a simple configuration, and the charging time for the driving lithium-ion battery 22 having a charge capacity sufficient to drive the electric device 2 can be shortened.

[0070] When the built-in lithium-ion battery 12 is electrically connected to the driving lithium-ion battery 22 , the built-in lithium-ion battery 12 applies a voltage to the driving lithium-ion battery 22 that is equal to or lower than the maximum charging voltage of the driving lithium-ion battery 22 .

[0071] Before being electrically connected to the driving lithium-ion battery 22, the built-in lithium-ion battery 12 is charged with power supplied from an external power source C. At this time, the built-in lithium-ion battery 12 is charged at a charging voltage that is equal to or lower than the maximum charging voltage of the built-in lithium-ion battery 12. After the built-in lithium-ion battery 12 is charged, the voltage output by the built-in lithium-ion battery 12 is lower than the charging voltage. When the built-in lithium-ion battery 12 is electrically connected to the driving lithium-ion battery 22, the built-in lithium-ion battery 12 applies a voltage to the driving lithium-ion battery 22 that is equal to or lower than the maximum charging voltage of the driving lithium-ion battery 22.

[0072] [Configuration example of driving lithium-ion battery] Fig. 2(a) is a diagram showing a configuration example of the driving lithium-ion battery 22 shown in Fig. 1. The driving lithium-ion battery in Fig. 2(a) is an example of the driving lithium-ion battery 22 shown in Fig. 1, but to make it easier to understand the functions, the same reference numerals as in Fig. 1 are used in the following description.

[0073] The driving lithium-ion battery 22 includes multiple lithium-ion battery cells 22c. The driving lithium-ion battery 22 also includes an electrical connector 22e and multiple bus bars 22b. The lithium-ion battery cells 22c are connected in series, without being connected in parallel, for example. The lithium-ion battery cells 22c of the driving lithium-ion battery 22 have a series-connection structure without parallel connections. Each lithium-ion battery cell 22c has a variation in internal resistance. However, the current flowing through each series-connected lithium-ion battery cell 22c is substantially equal regardless of the difference in internal resistance. This makes it easy to maintain a balance in the charge levels of each lithium-ion battery cell 22c. For example, when charging is started from a state in which each lithium-ion battery cell 22c has a zero charge level, the integrated current levels of each lithium-ion battery cell 22c at any given time are substantially equal. In other words, the charge levels of each lithium-ion battery cell 22c are substantially equal. In this way, by eliminating the parallel connection of the lithium-ion battery cells 22c, the circuitry for monitoring each lithium-ion battery cell 22c can be simplified or eliminated, resulting in a simple and compact configuration for the driving lithium-ion battery 22. The lithium-ion battery cells 22c have a charge capacity of 2.5 Ah or more.

[0074] The lithium-ion battery cell 22c contains, for example, lithium oxide in the positive electrode. The lithium-ion battery cell 22c is a non-aqueous lithium-ion battery that uses a non-aqueous electrolyte. The maximum charging current of the lithium-ion battery cell 22c is higher than the maximum charging current of a battery of the same size that uses other positive electrode materials, such as a lead battery or a nickel-metal hydride battery. The lithium-ion battery cell 22c can be charged at a rate of, for example, 10 C or higher. The driving lithium-ion battery 22 has a negative electrode 22n. More specifically, each lithium-ion battery cell 22c has a negative electrode 22n. The negative electrode 22n contains at least one selected from the group consisting of spinel-type lithium titanate, a niobium-titanium-containing composite oxide, and graphite. The negative electrode 22n of the driving lithium-ion battery 22 contains, for example, a niobium-titanium-containing composite oxide. Such a driving lithium-ion battery 22 has a large maximum charging current. For example, the maximum charging current value of the driving lithium-ion battery 22 is smaller than the maximum discharging current value, similar to that of a general secondary battery. However, the difference between the maximum charging current value and the maximum discharging current value of the driving lithium-ion battery 22 is 30% or less of the maximum charging current value. The standard operating voltage of each lithium-ion battery cell 22c is, for example, 2.3 V. Each lithium-ion battery cell 22c can be charged at a voltage exceeding the standard operating voltage. Each lithium-ion battery cell 22c can be charged at a voltage of, for example, 2.6 V. The maximum charging voltage of the lithium-ion battery cell 22c is 2.6 V.

[0075] The electrical connector 22e is connected to the charging connector 21. The driving lithium-ion battery 22 is charged by connecting the storage-type charging device 1 to the charging connector 21. The power stored in the driving lithium-ion battery 22 is supplied to the driving device 25. The driving device 25, which receives power from the charged driving lithium-ion battery 22, is connected to the driving lithium-ion battery 22 via, for example, the electrical connector 22e. However, the connection to the driving device 25 is not limited to this. For example, the driving lithium-ion battery 22 may have a connector for connecting to the driving device 25 that is different from the electrical connector 22e. The bus bar 22b is a thick, plate-shaped conductor. The bus bar 22b connects the lithium-ion battery cells 22c and the electrical connector 22e in series. The bus bar 22b connects the lithium-ion battery cells 22c in series without being connected in parallel. The conductor is not limited to the bus bar 22b, and for example, a wire may be used. The bus bar 22b has an electrical resistance smaller than that of a wire having the same conductor diameter and the same length as the thickness of the bus bar 22b. Therefore, when the bus bar 22b is used, the electrical resistance of the conductor is reduced, and the driving lithium-ion battery 22 can be charged in a shorter time.

[0076] [Configuration example of built-in lithium-ion battery] Figure 2(b) is a diagram showing a configuration example of built-in lithium-ion battery 12 shown in Figure 1. Built-in lithium-ion battery 12 in Figure 2(b) is an example of built-in lithium-ion battery 12 shown in Figure 1, but to make it easier to understand the functions, the same reference numerals as in Figure 1 are used in the following description.

[0077] The built-in lithium-ion battery 12 includes multiple lithium-ion battery cells 12c. The built-in lithium-ion battery 12 also includes an electrical connector 12e and multiple bus bars 12b. The lithium-ion battery cells 12c are, for example, connected in series without being connected in parallel. The lithium-ion battery cells 12c of the built-in lithium-ion battery 12 have a series-connection structure without parallel connections. The lithium-ion battery cells 12c have variations in internal resistance. However, the current flowing through each of the series-connected lithium-ion battery cells 12c is substantially equal regardless of the difference in internal resistance. This makes it easy to maintain a balance in the charge levels of the lithium-ion battery cells 12c. For example, when charging is started from a state in which each lithium-ion battery cell 12c has a zero charge level, the integrated current levels of each lithium-ion battery cell 12c at any given time are substantially equal. In other words, the charge levels of each lithium-ion battery cell 12c are substantially equal. By eliminating the parallel connection of the lithium-ion battery cells 12c, the circuitry for monitoring each lithium-ion battery cell 12c can be simplified or eliminated, allowing the built-in lithium-ion battery 12 to be compact with a simple configuration.By eliminating the parallel connection of the lithium-ion battery cells 12c, the circuitry for monitoring each lithium-ion battery cell 12c can be simplified or eliminated, allowing the built-in lithium-ion battery 12 to be compact with a simple configuration.

[0078] The lithium-ion battery cell 12c contains, for example, lithium oxide in the positive electrode. The lithium-ion battery cell 12c is a non-aqueous lithium-ion battery that uses a non-aqueous electrolyte. The maximum charging current of the lithium-ion battery cell 12c is higher than the maximum charging current of batteries of the same size that use other positive electrode materials, such as lead batteries or nickel-metal hydride batteries. The lithium-ion battery cell 12c can be charged at a rate of 10 C or higher for a charge capacity of, for example, 2.5 Ah. The internal lithium-ion battery 12 has a negative electrode 12n. More specifically, each lithium-ion battery cell 12c has a negative electrode 12n. The negative electrode 12n contains at least one selected from the group consisting of spinel-type lithium titanate, niobium-titanium-containing composite oxide, and graphite. The negative electrode 12n of the internal lithium-ion battery 12 contains, for example, niobium-titanium-containing composite oxide. Such an internal lithium-ion battery 12 has a large maximum charging current. For example, the maximum charging current value of the built-in lithium-ion battery 12 is smaller than the maximum discharging current value, as with general secondary batteries. However, the difference between the maximum charging current value and the maximum discharging current value of the built-in lithium-ion battery 12 is 30% or less of the maximum charging current value. The standard operating voltage of each lithium-ion battery cell 12c is, for example, 2.3 V. Each lithium-ion battery cell 12c can be charged at a voltage exceeding the standard operating voltage. Each lithium-ion battery cell 12c can be charged at a voltage of, for example, 2.6 V. The maximum charging voltage of the lithium-ion battery cell 22c is 2.6 V. Hereinafter, the lithium-ion battery cells 22c and the lithium-ion battery cells 12c will be collectively referred to simply as battery cells.

[0079] The standard operating voltage, maximum charge voltage, and maximum discharge voltage of the built-in lithium-ion battery 12 and the driving lithium-ion battery 22 shown in FIG. 1 are determined by the number of battery cells connected in series. The maximum charge voltage is the maximum voltage that can be applied during charging. The maximum discharge voltage is the maximum voltage that can be output during discharging. The standard operating voltage is the nominal voltage that is normally used. The standard operating voltage is a voltage that is determined by the battery manufacturer as a specification standard based on the characteristics of the battery cells. In contrast, the maximum charge voltage and maximum discharge voltage are voltages that are technically derived from the characteristics of the battery cells.

[0080] [Example of Battery Cell Combination] Here, as an example of the built-in lithium-ion battery 12 and the driving lithium-ion battery 22 used in the charging system A shown in FIG. 1, an example in which 20 battery cells of 2.4 Ah are connected in series will be described.

[0081] For example, the driving lithium-ion battery 22 shown in FIG. 2( a) has 20 lithium-ion battery cells 22c. The maximum charging voltage of the driving lithium-ion battery 22 is 52V. The internal lithium-ion battery 12 shown in FIG. 2( b) has 20 lithium-ion battery cells 12c. The maximum charging voltage of the internal lithium-ion battery 12 is also 52V. The maximum discharge voltage of the internal lithium-ion battery 12 is lower than the maximum charging voltage to which the internal lithium-ion battery 12 can be charged. The maximum discharge voltage is the maximum voltage output by the internal lithium-ion battery 12 during discharging. More specifically, the maximum discharge voltage of the internal lithium-ion battery 12 is lower than the maximum charging voltage to which the internal lithium-ion battery 12 can be charged by the amount of voltage loss due to internal resistance and relaxation resistance. The internal resistance and relaxation resistance are parasitic resistance components of each cell that constitutes the battery. Due to voltage loss due to the internal resistance and relaxation resistance, the maximum discharge voltage of the internal lithium-ion battery 12 is typically 0.8 to 0.95 times the maximum charging voltage. The maximum discharge voltage of the built-in lithium-ion battery 12 provided in the storage-type charging device 1 that charges the electrical device 2 is equal to or lower than the maximum charge voltage of the driving lithium-ion battery 22 provided in the electrical device 2. In other words, the built-in lithium-ion battery 12 has a maximum discharge voltage equal to or lower than the maximum charge voltage of the driving lithium-ion battery 22. The built-in lithium-ion battery 12 has a maximum charge voltage based on the maximum discharge voltage of the built-in lithium-ion battery 12 described above. More specifically, the value of the maximum charge voltage of the built-in lithium-ion battery 12 is less than 1 / 0.8 times the maximum discharge voltage of the built-in lithium-ion battery 12 described above. In other words, the value of the maximum charge voltage of the built-in lithium-ion battery 12 is less than 1 / 0.8 times the maximum charge voltage of the driving lithium-ion battery 22 described above. The voltage to which the built-in lithium-ion battery 12 discharges is equal to or lower than the maximum charge voltage of the driving lithium-ion battery 22. The built-in lithium-ion battery 12 outputs a voltage that allows the driving lithium-ion battery 22 to be charged at the maximum current during use. The voltage output by the built-in lithium-ion battery 12 decreases as the charging of the drive lithium-ion battery 22 progresses.However, the driving lithium-ion battery 22 is charged in a short time because it is charged at the maximum current during use, which corresponds to a rate of 10 C or more. The driving lithium-ion battery 22 is charged within the time period in which the voltage of the built-in lithium-ion battery 12 is maintained within the chargeable range.

[0082] Because the lithium-ion battery cells 12c in the internal lithium-ion battery 12 are connected in series, the amount of current output from the internal lithium-ion battery 12 is the same as the amount of current flowing through each of the lithium-ion battery cells 12c. The amount of current received by the internal lithium-ion battery 12 from an external source is the same as the amount of current flowing through each of the lithium-ion battery cells 12c. Therefore, as long as the standard operating voltage, maximum charging voltage, and maximum discharging voltage of the internal lithium-ion battery 12 are set in proportion to the number of lithium-ion battery cells 12c, the capacity (Ah) of the internal lithium-ion battery 12 is substantially the same as the capacity of each of the lithium-ion battery cells 12c. For example, if the internal lithium-ion battery 12 has ten lithium-ion battery cells 12c connected in series, each of which has a standard operating voltage of 2.3V and a charging capacity of 2.5Ah, the internal lithium-ion battery 12 has a standard operating voltage of 23V. The internal lithium-ion battery 12 also has a charging capacity of 2.5Ah. The built-in lithium-ion battery 12 has substantially the same charge capacity as each of the lithium-ion battery cells 12c. However, because the standard operating voltage of the built-in lithium-ion battery 12 is 10 times that of the lithium-ion battery cells 12c, the amount of power stored in the built-in lithium-ion battery 12 is 10 times that of each of the lithium-ion battery cells 12c. The capacity relationship in a series connection can also be applied to the driving lithium-ion battery 22. The standard operating voltage and number of battery cells of the driving lithium-ion battery 22 are determined at the time of design according to the specifications of the electrical device 2. The standard operating voltage of the built-in lithium-ion battery 12 is determined at the time of design, taking into account the charging time for the driving lithium-ion battery 22.

[0083] The driving lithium-ion battery 22 and the internal lithium-ion battery 12 in the above-described example can be charged with a large current. FIG. 2C is a chart showing the maximum currents of the driving lithium-ion battery 22 and the internal lithium-ion battery 12. For example, the maximum charging current of the driving lithium-ion battery 22 is smaller than the maximum discharging current of the internal lithium-ion battery 12. More specifically, the maximum charging current of the driving lithium-ion battery 22 and the internal lithium-ion battery 12 is smaller than the maximum discharging current, as with general secondary batteries. However, the difference between the maximum charging current and the maximum discharging current of the driving lithium-ion battery 22 and the internal lithium-ion battery 12 is 30% or less of the maximum charging current. The maximum charging current corresponds to a rate of 10 C or higher. Note that when the driving lithium-ion battery 22 and the internal lithium-ion battery 12 are connected via a large-current-passing current output path 14 without a voltage converter, the voltage output from the internal lithium-ion battery 12 is smaller than the maximum output voltage of the internal lithium-ion battery 12. Therefore, the current flowing from the built-in lithium-ion battery 12 to the driving lithium-ion battery 22 is smaller than the maximum charging current value. However, as described above, the maximum charging current value corresponds to a rate of 10 C or more, so charging is completed in a short time.

[0084] If the built-in lithium-ion battery 12 and the driving lithium-ion battery 22 each have a common maximum discharge current value and maximum charge current value, management of the battery cells during manufacturing and maintenance is easy.

[0085] Electrical connector 12e is connected to charging object connection part 11 (see FIG. 1 ). The power stored in built-in lithium ion battery 12 is supplied to charging object connection part 11 through electrical connector 12e. Built-in lithium ion battery 12 also receives a supply of power from external power source C via electrical connector 12e. Note that the connection to external power source C is not particularly limited; for example, built-in lithium ion battery 12 may have a connector for connection to external power source C that is different from electrical connector 12e.

[0086] In the above-described configuration example, the driving lithium-ion battery 22 includes 20 lithium-ion battery cells 22c each having a capacity of 2.4 Ah, and the built-in lithium-ion battery 12 includes 20 lithium-ion battery cells 12c each having a charge capacity of 2.4 Ah. The capacities and numbers of battery cells that can be used are not limited to these. Next, modifications will be described.

[0087] The battery cells of the driving lithium-ion battery 22 and the internal lithium-ion battery 12 are assumed to have a charge capacity of, for example, 5 Ah. Even in this case, the lithium-ion battery cells 22c of the driving lithium-ion battery 22 are assumed to be battery cells capable of being charged at a maximum current during use corresponding to a rate of 10 C or higher for a charge capacity of 2.5 Ah. The lithium-ion battery cells 12c of the internal lithium-ion battery 12 are assumed to be battery cells capable of being discharged at a maximum current during use corresponding to a rate of 10 C or higher for a charge capacity of 2.5 Ah. However, if the driving lithium-ion battery 22, which has a charge capacity of 5 Ah, can be charged at a maximum current during use corresponding to a rate of 10 C or higher for a charge capacity of 5 Ah, and the internal lithium-ion battery 12, which has a charge capacity of 5 Ah, can be discharged at a maximum current during use corresponding to a rate of 10 C or higher for a charge capacity of 5 Ah, then half the power of the 5 Ah charge capacity can be charged in approximately 3 minutes or less.

[0088] [Variation 2] The maximum current during use at which the driving lithium-ion battery 22 is charged and the maximum current during use at which the built-in lithium-ion battery 12 is discharged correspond to a rate of, for example, 20 C or higher. In this case, the driving lithium-ion battery 22 is charged in an even shorter time.

[0089] [Variation 3] For example, in a configuration in which the driving lithium-ion battery 22 has a lithium-ion battery cell 22c with a capacity of 5 Ah and the internal lithium-ion battery 12 has a lithium-ion battery cell 12c with a capacity of 5 Ah, if a charging current of 100 A or more is supplied from the internal lithium-ion battery 12 to the driving lithium-ion battery 22, the charge and discharge rate is 20 C or higher. Also, in a configuration in which the driving lithium-ion battery 22 has a lithium-ion battery cell 22c with a capacity of 20 Ah and the internal lithium-ion battery 12 has a lithium-ion battery cell 12c with a capacity of 20 Ah, if a charging current of 400 A or more is supplied from the internal lithium-ion battery 12 to the driving lithium-ion battery 22, the charge and discharge rate is 20 C or higher.

[0090] [Variation 4] The charge capacity of the driving lithium-ion battery 22 may be different from that of the built-in lithium-ion battery 12. The charge capacity of the built-in lithium-ion battery 12 may be equal to or greater than that of the driving lithium-ion battery 22. For example, if the charge capacity of the built-in lithium-ion battery 12 is greater than that of the driving lithium-ion battery 22, it is possible to charge the electrical device 2 multiple times without charging the storage-type charging device 1.

[0091] [Variation 5] The number of lithium-ion battery cells 22c in the driving lithium-ion battery 22 and the number of lithium-ion battery cells 12c in the built-in lithium-ion battery 12 can be set according to the maximum charging voltage. The maximum discharge voltage to which the driving lithium-ion battery 22 can be charged is set within the range of 12 V to 72 V. For example, if the driving lithium-ion battery 22 is configured by connecting five lithium-ion battery cells 22c in series, each having a maximum discharge voltage of 2.8 V, the maximum discharge voltage to which the driving lithium-ion battery 22 can be discharged is 14 V. If the driving lithium-ion battery 22 is configured by connecting 26 lithium-ion battery cells 22c in series, the maximum discharge voltage to which the driving lithium-ion battery 22 can be discharged is approximately 72 V. The above voltage settings can also be applied to the built-in lithium-ion battery 12.

[0092] [Variation 6] The number of lithium-ion battery cells 22c in the driving lithium-ion battery 22 may differ from the number of lithium-ion battery cells 12c in the internal lithium-ion battery 12. For example, the number of lithium-ion battery cells 12c in the internal lithium-ion battery 12 may be greater than the number of lithium-ion battery cells 22c in the driving lithium-ion battery 22. In this case, the maximum charging voltage of the internal lithium-ion battery 12 is greater than the maximum charging voltage of the driving lithium-ion battery 22. The internal lithium-ion battery 12 may be configured so that its maximum output voltage is smaller than the maximum charging voltage of the driving lithium-ion battery 22. For example, the driving lithium-ion battery 22 may have 20 lithium-ion battery cells 22c with a capacity of 5 Ah, and the internal lithium-ion battery 12 may have 21 lithium-ion battery cells 12c with a charging capacity of 5 Ah. The internal lithium-ion battery 12 can be charged at a voltage 5% higher than that of the driving lithium-ion battery 22. In this case, the maximum discharge voltage of the built-in lithium-ion battery 12 is 0.8 to 0.95 times the charge voltage, which is less than the maximum charge voltage of the driving lithium-ion battery 22. If the number of lithium-ion battery cells 12c in the built-in lithium-ion battery 12 is within 5% more than or equal to the number of lithium-ion battery cells 22c in the driving lithium-ion battery 22, the maximum charge voltage of the built-in lithium-ion battery 12 and the lithium-ion battery cells 22c can be effectively utilized. Note that this number of battery cells can be applied to any configuration with any charge capacity and C rate.

[0093] [Variation 7] For example, if built-in lithium-ion battery 12 and driving lithium-ion battery 22 used in charging system A both have a positive electrode containing lithium oxide, and further have a negative electrode 22n containing at least one selected from the group consisting of spinel-type lithium titanate, niobium-titanium-containing composite oxide, and graphite, maintenance of built-in lithium-ion battery 12 and driving lithium-ion battery 22 used in charging system A will be easier. Also, in this case, in a configuration in which the maximum discharge voltage of built-in lithium-ion battery 12 is lower than the maximum charge voltage of driving lithium-ion battery 22, the maximum current during use at a rate of 10 C or higher for a charge capacity of 2.5 Ah can be set via current output path 14 without going through a voltage converter, making it easy to manufacture the battery cell.

[0094] The built-in lithium-ion battery 12 may, for example, satisfy a high-current charging specification in addition to a high-current discharging specification. For example, the difference between the current value (maximum discharging current value) of the high-current discharging specification and the current value (maximum charging current value) of the high-current charging specification is smaller than the smaller of the maximum discharging current value or the maximum charging current value. Furthermore, the driving lithium-ion battery 22 may, for example, satisfy a high-current discharging specification in addition to a high-current charging specification. For example, the difference between the maximum discharging current value and the maximum charging current value is smaller than the smaller of the maximum discharging current value or the maximum charging current value. In this case, when power stored in the built-in lithium-ion battery 12 is supplied to the driving lithium-ion battery 22 without the intervention of a voltage converter to charge the driving lithium-ion battery 22, a situation in which the supply current is limited to less than half due to the low-current discharging specification is suppressed. This allows the driving lithium-ion battery 22 to be charged in a short time.

[0095] For example, the decrease in supply current can be more effectively suppressed if the difference between the maximum discharge current and the maximum charge current of the built-in lithium-ion battery 12 is 30% or less of the smaller of the two. Also, the decrease in supply current can be more effectively suppressed if the difference between the maximum discharge current and the maximum charge current of the driving lithium-ion battery 22 is 30% or less of the smaller of the two.

[0096] As shown in FIG. 2( b), the built-in lithium-ion battery 12 may include a current breaker 12d connected in series with multiple lithium-ion battery cells 12c to interrupt the current flowing through the multiple lithium-ion battery cells 12c. The current breaker 12d prevents current from the multiple lithium-ion battery cells 12c from accidentally flowing to the outside. For example, suppose the charge target connection unit 11 accidentally comes into contact with a conductor outside the energy storage type charging device 1 when it is removed from the electric device 2 or while being attached to the electric device 2. This prevents a large current from shorting and welding the conductor to the charge target connection unit 11. The current breaker 12d breaks the current when a current greater than a predetermined allowable current flows from the built-in lithium-ion battery 12 to the current output path 14. The current breaker 12d breaks and connects the current depending on the value of the current flowing through the built-in lithium-ion battery 12. However, this does not function to switch the path through which a large current passes from the current output path 14 to another path in accordance with the potential difference between the driving lithium-ion battery 22 and the built-in lithium-ion battery 12 when the driving lithium-ion battery 22 is being charged with a large current. The current breaker 12d only interrupts the circuit of the built-in lithium-ion battery 12, and after interruption, the driving lithium-ion battery 22 cannot be discharged for charging, so this does not constitute path switching for charging. The driving lithium-ion battery 22 may also be equipped with a current breaker 22d connected in series with multiple lithium-ion battery cells 22c as shown in FIG. 2(a) to interrupt the current flowing through the multiple lithium-ion battery cells 22c. Again, this does not function to switch the path through which a large current passes from the current output path 14 to another path in accordance with the potential difference between the driving lithium-ion battery 22 and the built-in lithium-ion battery 12 when the driving lithium-ion battery 22 is being charged with a large current.

[0097] The lithium-ion battery cells 12c included in the built-in lithium-ion battery 12 are connected in series, not in parallel. The internal resistances of the lithium-ion battery cells 12c vary. However, the currents flowing through the series-connected lithium-ion battery cells 12c are substantially equal regardless of the differences in internal resistance. This makes it easy to maintain a balance in the charge levels of the lithium-ion battery cells 12c. For example, when charging is started from a state in which each lithium-ion battery cell 12c has zero charge, the integrated currents of the lithium-ion battery cells 12c at any given time are substantially equal. That is, the charge levels of the lithium-ion battery cells 12c are substantially equal. Furthermore, even when each lithium-ion battery cell 12c is discharging, the currents flowing through the lithium-ion battery cells 12c are substantially equal. Therefore, the charge levels of the lithium-ion battery cells 12c at any given time are substantially equal. Therefore, the timing at which each lithium-ion battery cell 12c reaches full charge during charging is also substantially equal. Therefore, even if the control device 25b (see FIG. 3) for monitoring and controlling the state of each lithium-ion battery cell 12c is simple and small, it is possible to maintain a balance in the charge amounts of each lithium-ion battery cell 12c. Therefore, the storage type charging device 1 can be made compact with a simple configuration.

[0098] The maximum voltage specification (maximum charging voltage) at which the built-in lithium-ion battery 12 can be charged is between 12 V and 72 V. In this case, the maximum voltage that can be applied across the multiple lithium-ion battery cells 12c connected in series is 72 V or less. For example, the maximum voltage that can be applied across 20 lithium-ion battery cells 12c connected in series is 58 V.

[0099] [Variation 8] The compatible battery detection and switch unit 13 detects that a driving lithium-ion battery 22 that meets the maximum operating voltage and high-current charging specifications has been connected by connecting the output connector 11b to the charging connector 21, which has a structure specific to the battery's attributes. For example, the charging connector 21 has a shape specific to the specifications of the driving lithium-ion battery 22. In other words, the shape of the charging connector 21 is different from the shape of a connector for a battery with specifications different from those of the driving lithium-ion battery 22. The output connector 11b is connectable to the charging connector 21 with this specific shape, and the compatible battery detection and switch unit 13 is configured to detect that the output connector 11b has been connected to the charging connector 21. By detecting that the output connector 11b has been connected to the charging connector 21, the compatible battery detection and switch unit 13 detects that a driving lithium-ion battery 22 that meets the maximum operating voltage and high-current charging specifications has been connected. In this case, the configuration for information storage, communication, and determination processing can be simplified compared to when information is obtained via communication.

[0100] [Application Example] Figure 3 is a diagram illustrating an application example of the storage-type charging device and charging system shown in Figure 1. Figure 3(a) is a block diagram showing the state of pre-charging of the storage-type charging device 1. Figure 3(b) is a block diagram showing the state of charging of the drive lithium-ion battery 22 by the storage-type charging device 1. Figure 3 shows a saddle-ride type vehicle 2' as an example of an electric device. The saddle-ride type vehicle 2' includes a motor 25a as a drive device 25 and a control device 25b for the motor 25a. The reference numerals of the remaining elements in the charging system A are the same as those of the corresponding elements in Figure 1, and differences from the configuration in Figure 1 will be particularly described.

[0101] First, the built-in lithium-ion battery 12 of the storage type charging device 1 is charged with power supplied from an external power source Cb. For example, a precedence charging unit Ca is provided outside the storage type charging device 1 and the saddle riding type vehicle 2'. The precedence charging unit Ca charges the built-in lithium-ion battery 12 at a voltage equal to or lower than the maximum charging voltage of the drive lithium-ion battery 22 using power supplied from a commercial AC power source, which is the power source Cb external to the storage type charging device 1 and the saddle riding type vehicle 2'. The built-in lithium-ion battery 12 is charged to an internal battery voltage equal to or lower than the maximum charging voltage.

[0102] After the built-in lithium-ion battery 12 has been charged, when the charging object connector 11 is connected to the driving lithium-ion battery 22, the built-in lithium-ion battery 12 is electrically connected to the driving lithium-ion battery 22. By connecting the charging object connector 11 to the driving lithium-ion battery 22, the compatible battery detection and switch section 13 passes the current output from the built-in lithium-ion battery 12 through the current output path 14. Current flows from the built-in lithium-ion battery 12 to the driving lithium-ion battery 22. The driving lithium-ion battery 22 is charged at a charge rate of 10C or higher.

[0103] [Second embodiment] Fig. 4 is a block diagram showing the schematic configuration of a storage-type charging device according to a second embodiment. The storage-type charging device 3 shown in Fig. 4 differs from the storage-type charging device 1 shown in Fig. 1 in that it has a built-in precedence charging unit Ca'. The precedence charging unit Ca' charges the built-in lithium-ion battery 12 with power supplied from a commercial AC power source, which is an external power source Cb.

[0104] The above-described modified examples may be applied individually to each embodiment, or may be applied in combination. Any two modified examples from Modification 1 to Modification 8 may be applied to each embodiment. Any three modified examples from Modification 1 to Modification 8 may be applied to each embodiment. Any four modified examples from Modification 1 to Modification 8 may be applied to each embodiment. Any five modified examples from Modification 1 to Modification 8 may be applied to each embodiment. Any six modified examples from Modification 1 to Modification 8 may be applied to each embodiment.

[0105] REFERENCE SIGNS LIST 1 Energy storage type charging device 2, 2' Electrical device 3 Energy storage type charging device 11 Charging target connection section 12 Built-in lithium ion battery 12b Bus bar 12c Lithium ion battery cell 12n Negative electrode 13 Compatible battery detection and switch section 14 Current output path 17 Compatible battery detection section 18 Output switch section 22 Driving lithium ion battery 22b Bus bar 22c Lithium ion battery cell 22n Negative electrode A Charging system

Claims

1. A storage-type charging device that has a large-current rechargeable lithium-ion battery mounted thereon and is detachably connected to an electrical device driven by the power of the large-current rechargeable lithium-ion battery to charge the large-current rechargeable lithium-ion battery, the storage-type charging device comprising: a charging object connection part that electrically connects with the large-current rechargeable lithium-ion battery; a large-current dischargeable built-in lithium-ion battery that is provided in the storage-type charging device and is charged with power supplied from a power source external to the storage-type charging device and the electrical device, and that meets large-current discharge specifications; and a large-current passing current output path that connects the large-current dischargeable built-in lithium-ion battery and the charging object connection part without going through a voltage converter, and is characterized as follows: The storage-type charging device comprises: a compatible battery detection and switch unit that is provided in the large-current passing current output path and that, upon detecting that the large-current rechargeable driven lithium-ion battery that satisfies maximum voltage specifications during use and large-current charging specifications has been connected to the charging target connection unit and turning on, passes the large current to the large-current passing current output path without passing through the voltage converter so that the large-current rechargeable driven lithium-ion battery is charged with the large current output from the large-current dischargeable built-in lithium-ion battery; the storage-type charging device is configured not to have a function for switching the path through which the large current passes from the large-current passing current output path to another path during charging with the large current, depending on the potential difference between the large-current rechargeable driven lithium-ion battery and the large-current dischargeable built-in lithium-ion battery; the large-current discharge specification means a battery specification that allows for discharging at a maximum current during use corresponding to a rate of 10 C or more for a charge capacity of 2.5 Ah; and the large-current charge specification means a battery specification that allows for charging at a maximum current during use corresponding to a rate of 10 C or more for a charge capacity of 2.5 Ah. The large current is a current corresponding to a rate of 10 C or more for a charge capacity of 2.5 Ah.

2. The storage-type charging device according to claim 1, wherein the storage-type charging device detects that the large-current rechargeable driven lithium-ion battery that satisfies the maximum operating voltage specification and the large-current charging specification has been connected to the charging object connection part by detecting that the charging object connection part has been mechanically connected to the large-current rechargeable driven lithium-ion battery or the electrical device, or by communicating with the electrical device and acquiring information representing the attributes of the large-current rechargeable driven lithium-ion battery.

3. A storage-type charging device according to claim 1 or 2, wherein the built-in lithium-ion battery capable of large current discharge has a negative electrode containing at least one selected from the group consisting of spinel-type lithium titanate, niobium-titanium-containing composite oxide, and graphite.

4. A storage-type charging device according to any one of claims 1 to 3, wherein the large-current rechargeable drive lithium-ion battery has a negative electrode containing at least one selected from the group consisting of spinel-type lithium titanate, niobium-titanium-containing composite oxide, and graphite.

5. A storage-type charging device according to any one of claims 1 to 4, further comprising a pre-charging section that charges the large-current dischargeable built-in lithium-ion battery at a voltage equal to or lower than the maximum charging voltage of the large-current chargeable drive lithium-ion battery using power supplied from a power source external to the storage-type charging device and the electrical device.

6. A charging system comprising: a storage-type charging device according to any one of claims 1 to 5; and an electrical device connected to the storage-type charging device and driven by the power of the high-current rechargeable driving lithium-ion battery charged by the storage-type charging device.

7. The high-current rechargeable driving lithium-ion battery mounted in the electrical device of the charging system according to claim 6 and charged by the storage-type charging device.

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