Abstract: A charge control device of one example of the present invention comprises a temperature detection unit, a storage unit, and an upper limit setting unit. The storage unit stores a reference current characteristic and at least one of a first current characteristic and a second current characteristic as a charging current characteristic, and stores a reference voltage characteristic and at least one of a first voltage characteristic and a second voltage characteristic as a charging voltage characteristic. The upper limit setting unit selects a characteristic used to set upper limits of a charging current and a charging voltage to the battery from among a plurality of the charging current characteristics and a plurality of the charging voltage characteristics stored in the storage unit.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An electrical device system having a battery pack, an electrical device, and a charging device, includes: a current detecting unit that detects a battery current flowing through the battery during a charge to or a discharge from the battery; a battery state detecting unit that detects at least one of a battery voltage and a temperature of a heat generating unit; and a determining unit that estimates an amount of change in at least one of the battery voltage and the temperature of the heat generating unit, based on the battery current, and calculates an amount of actual change in at least one of the battery voltage and the temperature of the heat generating unit, wherein the determining unit determines that the current detecting unit is abnormal, when the difference between the calculated amount of actual change and the estimated amount of change is a default value or more.

Abstract: A battery pack includes: a connecting portion connected to a battery charger; a battery chargeable by the battery charger connected to the connecting portion; an environment temperature detecting element detecting an environment temperature around the battery; and a control circuit. The control circuit periodically detects the environment temperature via the environment temperature detecting element and controls the battery charger to suspend starting of charging the battery or to temporarily discontinue charging the battery when a variation of the environment temperature detected exceeds a predetermined range, when the battery charger is connected to the connecting portion.

Abstract: A battery pack for power tool includes a battery, a monitoring circuit, and a sleep mode switching unit. The battery includes at least one battery cell. The monitoring circuit is operated by receiving power supply from the battery. The sleep mode switching unit switches the battery pack to a sleep mode by stopping at least a part or all of operations of the monitoring circuit when the monitoring circuit detects a discharge end state where a discharge current from the battery is equal to or lower than a predetermined set current value, and the monitoring circuit further detects at least one of a voltage stable state where a voltage change amount in the battery cell is within a predetermined stable range of voltage change amount and a temperature stable state where a temperature change amount in the battery is within a predetermined stable range of temperature change amount.

Abstract: A battery monitoring system for electric power tool includes a battery pack for electric power tool and an auxiliary power source. The battery pack has a battery and a monitoring circuit. The battery is provided with at least one battery cell. The monitoring circuit is operated by electric power supplied from the battery, and monitors a status of the battery. The auxiliary power source outputs electric power allowing the monitoring circuit to operate. The monitoring circuit is configured such that, when the monitoring circuit is unoperational with the electric power of the battery due to a decrease in a voltage of the battery, the monitoring circuit becomes operational by the electric power supplied from the auxiliary power source.

Abstract: 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.

Abstract: 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.

Abstract: Each of a battery charger and a battery pack has a microcomputer. The respective microcomputers mutually perform data communication while the battery pack is being charged by the battery charger, and confirm an operational state of the microcomputer of the communication counterpart (mutual operation confirmation) based on a result of the data communication. When an abnormality of one of the microcomputers is detected, the other microcomputer executes a predetermined process for stopping charging.

Abstract: An electric power tool includes a tool body and a battery pack. A terminal voltage setting unit of the tool body sets a voltage of a body side terminal to a first voltage when a command to drive a drive portion of the tool body is issued by a switch of the tool body. A voltage changing unit of the battery pack changes a voltage of a battery side terminal from the first voltage to a second voltage when supply of electric power from the battery pack to the drive portion is permitted.

Abstract: An electric power tool includes a tool body and a battery pack. A terminal voltage setting unit of the tool body sets a voltage of a body side terminal to a first voltage when a command to drive a drive portion of the tool body is issued by a switch of the tool body. A voltage changing unit of the battery pack changes a voltage of a battery side terminal from the first voltage to a second voltage when supply of electric power from the battery pack to the drive portion is permitted.

Abstract: Each of a battery charger and a battery pack has a microcomputer. The respective microcomputers mutually perform data communication while the battery pack is being charged by the battery charger, and confirm an operational state of the microcomputer of the communication counterpart (mutual operation confirmation) based on a result of the data communication. When an abnormality of one of the microcomputers is detected, the other microcomputer executes a predetermined process for stopping charging.

Abstract: A battery monitoring system for electric power tool includes a battery pack for electric power tool and an auxiliary power source. The battery pack has a battery and a monitoring circuit. The battery is provided with at least one battery cell. The monitoring circuit is operated by electric power supplied from the battery, and monitors a status of the battery. The auxiliary power source outputs electric power allowing the monitoring circuit to operate. The monitoring circuit is configured such that, when the monitoring circuit is unoperational with the electric power of the battery due to a decrease in a voltage of the battery, the monitoring circuit becomes operational by the electric power supplied from the auxiliary power source.

Abstract: A battery pack for power tool includes a battery, a monitoring circuit, and a sleep mode switching unit. The battery includes at least one battery cell. The monitoring circuit is operated by receiving power supply from the battery. The sleep mode switching unit switches the battery pack to a sleep mode by stopping at least a part or all of operations of the monitoring circuit when the monitoring circuit detects a discharge end state where a discharge current from the battery is equal to or lower than a predetermined set current value, and the monitoring circuit further detects at least one of a voltage stable state where a voltage change amount in the battery cell is within a predetermined stable range of voltage change amount and a temperature stable state where a temperature change amount in the battery is within a predetermined stable range of temperature change amount.