Makita Corporation

Hiroki Uesugi

Takuya Umemura

Masafumi Noda

Tadahiko Kobayakawa

Takayoshi Endo

Hidekazu Hayashi

Kazuya Tanaka

Hayato Kano

Hiroshi Hanai

Kohei Nakatani

A battery pack contains a plurality of battery cells that includes a first battery cell and a second battery cell; a first thermistor disposed closest to the first battery cell among the battery cells; a second thermistor disposed closest to the second battery cell among the battery cells. A case of the battery pack holds the battery cells, the first thermistor, and the second thermistor. The first battery cell is disposed such that at least one of the other battery cells is interposed between the first battery cell and a wall surface of the case in a direction orthogonal to a longitudinal direction of the first battery cell. The second battery cell is disposed such that none of the other battery cells is interposed between the second battery cell and the wall surface of the case in a direction orthogonal to a longitudinal direction of the second battery cell.

Battery pack having a film thermistor and a dip thermistor

A battery pack in one aspect of the present disclosure includes a first cell, a memory device, a target current calculator, and an information notifier. The memory device stores a maximum variation of a charging current value. The maximum variation is determined depending on a characteristic of the battery pack. The target current calculator calculates a newest value of a target current value based on (i) a previous value of the target current value and (ii) the maximum variation. The information notifier transmits a charge condition information including the newest value.

Battery pack, charging system, and method for controlling charging of battery pack

A battery pack in one aspect of the present disclosure includes a battery and a controller provided with a counter value. During discharge of the battery pack, the controller calculates an addition value in accordance with a total number of use of the battery pack under a specified condition. The controller updates the counter value by adding the addition value. The controller prohibits the discharge of the battery pack in response to the counter value reaching a protection threshold.

Battery pack and method of protecting battery pack

An electrically-driven working apparatus in one aspect of an embodiment of the present disclosure comprises: a battery; an abnormality detection unit; a power supply path; a first disconnection unit; a second disconnection unit; and a control unit. The control unit activates the first disconnection unit to disconnect the power supply path if either of an overload or an over discharge of the battery is detected by the abnormality detection unit, and subsequently determines whether discharge from the battery has stopped after activating the first disconnection unit, and activates the second disconnection unit to disconnect the power supply path if discharge from the battery has not stopped.

Electrically-driven working apparatus and method for protecting battery of electrically-driven working apparatus

A battery charger in one aspect of the present disclosure includes an attachment portion, a charging circuit, a positive electrode terminal, a negative electrode terminal, at least one signal input terminal, an analog value acquisition device, a charging current detector, a comparison processor, and a current value reflection processor. The current value reflection processor performs one of a variable determination process for reference values and an analog value correction process. The variable determination process is a process for the current value reflection processor to variably determine the reference value based on a value of a charging current detected by the charging current detector. The analog value correction process is a process for the current value reflection processor to correct an analog value to be used in a comparison by the comparison processor based on the value of the charging current detected by the charging current detector.

Battery charger and control method thereof

A battery-charge control device comprises an attachment-detecting unit, a temperature-obtaining unit, a voltage-obtaining unit, a threshold-value-determining unit, a determination unit, and a completion-processing unit. The threshold-value-determining unit determines, based on a battery temperature obtained by the temperature-obtaining unit, a completion-threshold-value corresponding to the battery temperature for determining necessity of charging when the attachment-detecting unit detects that the battery pack is attached to the battery charger. The determination unit performs a determination of whether a voltage obtained by the voltage-obtaining unit is equal to or greater than the completion-threshold-value determined by the threshold-value-determining unit when the attachment-detecting unit detects that the battery pack is attached to the battery charger. The completion-processing unit performs a specified battery-charge completion processing indicating unnecessity of charging of the battery by the battery charger when the determination unit determines that the obtained voltage is equal to or greater than the completion-threshold-value.

Battery-charge control device, battery charger and battery pack

A charge control device includes a voltage detector that detects a voltage of a battery, a temperature detector that detects a battery temperature, a voltage setting unit that sets at least one of a charge completion voltage and an abnormality determination voltage to a high temperature time voltage that is lower than a normal voltage when the battery temperature detected by the temperature detector is or is above a high temperature determination threshold set in advance, and a charging current limiting unit that reduces a charging current a charger supplies to the battery when the battery temperature is in a temperature range between a set temperature that is lower by a predetermined temperature than the high temperature determination threshold and the high temperature determination threshold and the battery voltage detected by the voltage detector is in a voltage range between the normal voltage and the high temperature time voltage.

Charge control device

A tool battery pack can include a current detection element for detecting a discharge current or a charge current, a monitoring section for inputting a current signal of the discharge current or the charge current through the current detection element and for inputting voltage signals of each cell battery, and a control microcomputer for performing discharge control or charge control based on the signals from the monitoring section. Further, the tool battery pack is constructed such that the current signal through the current detection element is input to both the monitoring section and the control microcomputer.

Growing community of inventors

Anjo, Japan

Hiroki Uesugi