Makita Corporation

Hisakazu Okabayashi

Masafumi Noda

Masaya Mizutani

Hitoshi Suzuki

Kazuyuki Sakakibara

Tadahiko Kobayakawa

Takayoshi Endo

Masaaki Fukumoto

Toru Yamada

Junichi Murakami

Tomoo Muramatsu

Youichi Kato

Yoshihiro Ishikawa

Mamoru Sakai

Hiroshi Hanai

Makihiro Kobayashi

Makoto Ito

A charger includes a first connection portion, a second connection portion, a power-supply circuit, an integration circuit, a storage device, a first calculation circuit, a threshold setting circuit, a detection circuit, and a reduction circuit. The power-supply circuit includes a heat-generating component. At a start of charging a battery, the first calculation circuit calculates a first detection threshold candidate based on a first correspondence data (or a first correlation data). The first detection threshold candidate corresponds to a first temperature threshold that is calculated, with a calculated integrated capacity assigned to a battery capacity, based on the first correspondence data. The threshold setting circuit sets the first detection threshold candidate as a detection threshold. The reduction circuit performs reduction of a charging current value in response to a detected temperature of the heat-generating component having become higher than or equal to the detection threshold.

Charger

A charging system in one aspect of the present disclosure includes a battery pack and a charger. The battery pack includes a battery and an information output circuit. The information output circuit outputs faulty state information in response to receiving a faulty state information request. The faulty state information indicates that the battery pack is in a first faulty state. The charger includes a charging power generation circuit, a charging control circuit, and a reception circuit. The charging control circuit transmits the faulty state information request. The reception circuit receives the faulty state information.

Charging system, battery pack, and charger

A charger according to one aspect of the present disclosure includes a current outputter, a first charge controller, and a second charge controller. The first charge controller receives a first required information from a first device in accordance with a first communication protocol. The first communication protocol requires at least a first minimum volume of communication to acquire the first required information from the first device. The second charge controller receives a second required information from a second device in accordance with a second communication protocol. The second communication protocol requires at least a second minimum volume of communication to acquire a second required information from the second device. The second minimum volume is smaller than the first minimum volume.

Charger, charging system, and method for controlling charge current

A charger () includes connecting parts (), a main converter (), charging paths (Cpa, Cpb), switching elements (SWa, SWb), and a charging-control part (). A first battery (Ba) having a first mounting part () and a second battery (Bb) having a second, different mounting part () are respectively mountable on the connecting parts (). The charging paths (Cpa, Cpb) respectively connect the main converter () to the connecting parts (). The switching elements (SWa, SWb) respectively connect or disconnect the charging paths (Cpa, Cpb) to/from the main converter (). The charging-control part () selects one of the batteries (Ba, Bb) as the charging target and sets the charging path, to which the charging target (Ba, Bb) is connected, to the connected state. Then, the charger () charges the charging target to a predetermined voltage using a charging current suited to the charging target.

A battery pack according to the present invention includes a battery, a control unit, a power supply circuit, and a supply source selection unit. The power supply circuit is configured to receive electric power selectively from one of the battery and a charger, and generate a voltage for driving the control unit. The supply source selection unit is configured to select the charger as a power supply source to the power supply circuit when the battery is in a state of being able to supply electric power to the power supply circuit, the battery pack is attached to the charger and it is possible to supply electric power to the power supply circuit also from the charger.

Battery pack

A random number generating device includes: a microcomputer; a first oscillator circuit that has a predetermined temperature characteristic and generates a clock serving as a basis of a behavior of the microcomputer; and an electronic circuit that has a temperature characteristic being different from the predetermined temperature characteristic of the first oscillator circuit and operates in accordance with a command from the microcomputer. The microcomputer measures an operating time of the electronic circuit based upon the clock generated by the first oscillator circuit and generates a random number based upon a result of the measurement.

Random number generating device

A battery pack for electric power tool is provided with a battery and a control circuit. The circuit includes a condition satisfaction determination unit, a continuation satisfaction determination unit, and a sleep-mode transition unit. The condition satisfaction determination unit determines whether each of at least one predetermined sleep-mode transition condition is satisfied, and determines whether an all-condition satisfaction state is present, which is a state wherein all of the at least one sleep-mode transition condition are satisfied. The continuation satisfaction determination unit determines whether the all-condition satisfaction state has continued for a predetermined period of time when the condition satisfaction determination unit determines that the all-condition satisfaction state is present. The transition unit stops part of operation of the circuit to shift the circuit to a sleep mode when the continuation satisfaction determination unit determines that the all-condition satisfaction state has continued for the predetermined period of time.

Battery pack for electric power tool, control circuit, and program

An internal temperature estimation unit, which reads a detected temperature of a cell of a battery for an electric power tool to estimate an internal temperature of the battery based on the detected temperature, includes: an initial-value setting device which reads, when a discharge/charge of the battery is started, the detected temperature and sets the detected temperature as an initial value; and a temperature increase amount calculation device which calculates a temperature increase amount of the cell of the battery based on a latest value of the detected temperature and the initial value set by the initial-value setting device; the internal temperature estimation unit outputs the temperature increase amount as an estimated value representing the internal temperature of the battery.

Internal temperature estimation unit for battery for electric power tool, and apparatus for electric power tool

A battery connection device is provided with an authentication data creating unit that creates authentication data, a conversion unit that performs a first conversion of the authentication data, a transmission unit that transmits the authentication data to a battery pack, a receiving unit that receives from the battery pack a battery-side conversion result that is data obtained after the authentication data is converted by the battery pack, a reverse conversion unit that, on an assumption that the battery pack creates the battery-side conversion result by performing the first conversion and a second conversion on the authentication data, performs a reverse conversion of the second conversion on the battery-side conversion result, and a determination unit that determines whether or not the battery pack is an authentic product by comparing a result of the reverse conversion with a result of the first conversion.

Battery pack for electric power tool, and battery connection device

A battery pack for an electric power tool includes a control device that determines the necessity of a balancing control to reduce difference in voltages of cells of a battery based upon voltages of the respective cells measured by a voltage measuring device. The control device controls a subject cell, which is subject to the balancing control to discharge via the discharging device when the balancing control is determined to be necessary. A voltage measuring device measures the voltages of the respective cells when a battery charger detecting device detects the connection of the battery charger in a state where the battery has not been connected to the battery charger for a predetermined specified period of time or more and power feeding to the electric power tool has not been performed for the specified period of time or more.

Battery pack for electric power tool with reduced difference in voltages of multiple cells constituting battery

A rechargeable battery pack attachable to a power tool includes a display element, a remaining capacity detection device, a remaining capacity display control device, an abnormality detection device, and an abnormality display control device. The display element is provided such that a lighted state thereof can be confirmed from outside. The remaining capacity detection device detects a remaining capacity of a rechargeable battery. The remaining capacity display control device displays the remaining capacity detected by the remaining capacity detection device by controlling the lighted state of the display element. The abnormality detection device detects an abnormality of the rechargeable battery. The abnormality display control device displays the abnormality of the rechargeable battery detected by the abnormality detection device by controlling the lighted state of the display element to an abnormality display state, which is different from a remaining capacity display state controlled by the remaining capacity display control device.

Rechargeable battery pack

A disclosed heat generation amount estimation unit is used for a battery for an electric power tool, and estimates a heat generation amount of the battery that is a power source of the electric power tool. The heat generation amount estimation unit includes a computation device, and is provided in an apparatus for electric power tool. The computation device periodically reads, either during a discharge from the battery or during a charge to the battery, a detected current from a current detection device, which detects a current corresponding to this point in time from among a discharge current and a charge current flowing through the battery, and adds/subtracts a heat generation amount equivalent value in accordance with a value of the read detected current. The computation device outputs the added/subtracted heat generation amount equivalent value as an estimated value representing the heat generation amount of the battery.

Heat generation amount estimation unit for battery for electric power tool, and apparatus for electric power tool

Battery charger () may include a power source circuit () for charging rechargeable batteries () when a battery pack () is connected directly to the battery charger or is connected thereto with an adapter () interposed therebetween. The adapter may include a discharging circuit () for discharging the rechargeable batteries. The adapter may also include a switch () for alternatively connecting the rechargeable batteries with the discharging circuit or the charging circuit of the battery charger. The battery pack may have a memory () storing a flag indicating whether a refresh process is required. The adapter may further include a control portion () for controlling the switch. When the battery pack has been connected to the battery charger via the adapter, the control portion may preferably controls the switch on the basis of the flag stored in the memory of the battery pack.

Apparatus for refreshing batteries

A battery pack ( ) includes an outer enclosure ( ) and a forked air passage ( ) for introducing cooling air via the intake port ( ) formed in an outer enclosure ( ), sending the air between cell groups ( ) and ( ) which contain cells ( ), and discharging it from the outer enclosure at discharge ports ( ). Two metallic radiator plates ( ) partially define the air passage so as to be in contact with the side cells ( ), whereas a circular radiator plate ( ) made of synthetic resin also partially define the air passage so as to be in contact with the center cells ( ). The contact areas of the side cells with the metallic radiator plates ( ) are varied in order to achieve even cooling of the cells. The upstream portion of the synthetic resin radiator plate has a thicker wall than the downstream portion to achieve the same purpose.

Growing community of inventors

Anjo, Japan

Hisakazu Okabayashi