Abstract: Provided is a semiconductor device capable of stably estimating an internal temperature of a battery. A semiconductor device coupled to a battery calculates entropy heat of the battery at a predetermined time by using a charging current of the battery and an internal temperature of the battery at a time before a predetermined time, calculates a heat generation amount of the battery from the charging current of the battery, calculates a heat radiation amount of the battery based on a temperature difference between the internal temperature at the time before the predetermined time and a surface temperature of the battery, and estimates an internal temperature of the battery at the predetermined time by using the entropy heat, the heat generation amount and the heat radiation amount.

Abstract: The present invention provides a motor driving method, a battery pack, and a semiconductor device capable of variable-controlling a bus voltage from a battery pack. A battery pack outputting a bus voltage to a positive voltage node using a negative voltage node as a reference, an inverter unit converting the bus voltage to AC voltage by switching according to a PWM signal and driving a motor, and a motor control unit generating the PWM signal are used. The motor control unit outputs a voltage instruction signal for instructing the bus voltage toward the battery pack. The battery pack variable-controls the number of cells coupled in parallel between the positive voltage node and the negative voltage node so as to obtain the bus voltage according to the voltage instruction signal.

Abstract: The present invention provides a motor driving method, a battery pack, and a semiconductor device capable of variable-controlling a bus voltage from a battery pack. A battery pack outputting a bus voltage to a positive voltage node using a negative voltage node as a reference, an inverter unit converting the bus voltage to AC voltage by switching according to a PWM signal and driving a motor, and a motor control unit generating the PWM signal are used. The motor control unit outputs a voltage instruction signal for instructing the bus voltage toward the battery pack. The battery pack variable-controls the number of cells coupled in parallel between the positive voltage node and the negative voltage node so as to obtain the bus voltage according to the voltage instruction signal.

Abstract: A battery driven system has a secondary battery, a main unit, a switch provided on a power source path or a signal path of the main unit, an impedance measurement circuit, a memory circuit, and an authentication circuit. The impedance measurement circuit measures the impedance of the secondary battery. The memory circuit holds a preset impedance characteristic of the secondary battery as collating data. The authentication circuit compares measurement data based on the measured result of the impedance measurement circuit with the collating data, thereby determining whether the secondary battery is suitable. It controls the switch to be turned off, when the secondary battery is not suitable.

Abstract: The present invention provides a motor driving method, a battery pack, and a semiconductor device capable of variable-controlling a bus voltage from a battery pack. A battery pack outputting a bus voltage to a positive voltage node using a negative voltage node as a reference, an inverter unit converting the bus voltage to AC voltage by switching according to a PWM signal and driving a motor, and a motor control unit generating the PWM signal are used. The motor control unit outputs a voltage instruction signal for instructing the bus voltage toward the battery pack. The battery pack variable-controls the number of cells coupled in parallel between the positive voltage node and the negative voltage node so as to obtain the bus voltage according to the voltage instruction signal.

Abstract: There is provided a battery pack including a current control element which is inserted in a discharge current path, and in which a thermostat and a heat sensitive resistance element whose resistance value increases in response to an increase in temperature are connected in parallel; and a detection unit that outputs an open signal indicating the opening of the contacts when it is detected that contacts of the thermostat are opened.

Abstract: A battery pack for an electrically powered tool includes: one or plural secondary batteries connected in series and/or in parallel; a current detection resistor in a current path through which a charge/discharge current flows into each secondary battery; an N-channel charge control FET and an N-channel discharge control FET in the current path so as to control the charge/discharge current; and a controller detecting the charge/discharge current flowing in the current detection resistor and controlling the charge and discharge control FETs based on the detection result. A threshold value indicating an overcurrent detection current with respect to the charge/discharge current is set in advance, and the controller compares the charge/discharge current detected by the current detection resistor with the threshold value, and when the detected charge/discharge current is the threshold value or more, determines that an overcurrent state is detected and turns off the charge and discharge control FETs.

Abstract: A battery pack includes a current control device that has a thermostat and a positive temperature coefficient device whose resistance increases as the temperature rises connected in parallel, the current control device being inserted into a discharge current path of a battery cell and a protection circuit that detects a voltage of the battery cell, detects an overcharge and over-discharge of the battery cell, and generates an overcharge detection signal and an over-discharge detection signal. In a normal state, a discharge current of the battery cell flows through the thermostat of the current control device. When the discharge current is large enough to damage the battery cell, the thermostat turns off and the discharge current flows through the positive temperature coefficient device. When the positive temperature coefficient device produces heat, a resistance of the positive temperature coefficient device increases and the discharge current is limited or interrupted.

Abstract: There is provided a battery pack including a current control element which is inserted in a discharge current path, and in which a thermostat and a heat sensitive resistance element whose resistance value increases in response to an increase in temperature are connected in parallel; and a detection unit that outputs an open signal indicating the opening of the contacts when it is detected that contacts of the thermostat are opened.

Abstract: A battery pack includes electric cells connected in series or in parallel between first and second lines, each of the electric cells having a battery cell, a control circuit which performs authentication processing, a communication block which is connected to the control circuit and superimposes a series binary data string on a battery output of the battery cell, and a switching element controlled by the control circuit. The control circuit generates its address. The control circuit of each electric cell transmits the series binary data string including the address to a main body via the communication block and the first and second lines for authentication on each electric cell. The switching element is turned on when the authentication is successful, and charging or discharging is performed. The switching element is turned off when the authentication is unsuccessful, and charging or discharging is banned.

Abstract: A battery pack includes a current control device that has a thermostat and a positive temperature coefficient device whose resistance increases as the temperature rises connected in parallel, the current control device being inserted into a discharge current path of a battery cell and a protection circuit that detects a voltage of the battery cell, detects an overcharge and over-discharge of the battery cell, and generates an overcharge detection signal and an over-discharge detection signal. In a normal state, a discharge current of the battery cell flows through the thermostat of the current control device. When the discharge current is large enough to damage the battery cell, the thermostat turns off and the discharge current flows through the positive temperature coefficient device. When the positive temperature coefficient device produces heat, a resistance of the positive temperature coefficient device increases and the discharge current is limited or interrupted.

Abstract: A battery pack for an electrically powered tool includes: one or plural secondary batteries connected in series and/or in parallel; a current detection resistor in a current path through which a charge/discharge current flows into each secondary battery; an N-channel charge control FET and an N-channel discharge control FET in the current path so as to control the charge/discharge current; and a controller detecting the charge/discharge current flowing in the current detection resistor and controlling the charge and discharge control FETs based on the detection result. A threshold value indicating an overcurrent detection current with respect to the charge/discharge current is set in advance, and the controller compares the charge/discharge current detected by the current detection resistor with the threshold value, and when the detected charge/discharge current is the threshold value or more, determines that an overcurrent state is detected and turns off the charge and discharge control FETs.

Abstract: A secondary cell residual capacity calculation method and a battery pack capable of calculating the secondary cell residual capacity is provided. The calculation method includes detecting a temperature of a plurality of secondary cells; detecting a current and a terminal voltage of the plurality of secondary cells; digitizing temperature, current, and terminal voltage; calculating a cell polarization voltage from the digitized temperature, current and terminal voltage; calculating an original cell voltage from both of the calculated cell polarization voltage and the detected terminal voltage; and calculating a residual capacity rate based on the calculated original cell voltage with reference to a prearranged residual capacity reference data table.

Abstract: A remaining capacity calculation method for a secondary battery and a battery pack are provided. Dischargeable electric power is accurately calculated and accuracy of a remaining capacity rate found by an electric power integration method may be improved by providing a remaining capacity calculation method for a secondary battery. The method includes calculating a consumed electric power by way of integration of voltage and current measured at a preset time interval when using the secondary battery; calculating an available dischargeable electric power by subtracting an energy loss and unavailable energy from a discharge electric power of the secondary battery; and calculating a remaining capacity rate from a ratio between the calculated electric power and the dischargeable electric power.

Abstract: A method of changing a secondary battery, a method of calculating a remaining capacity rate of the secondary battery, and a battery pack are provided. The method of charging a secondary battery includes the steps of: performing a detection of a charging rate of the secondary battery using an integrating method in which a battery capacity is calculated by integrating a current value or a power value of the secondary battery for a certain period of time, and a detection of the charging rate of the secondary battery using a voltage method in which a voltage value of the secondary battery is measured and the charging rate is calculated based on a correlation between the voltage value and the charging rate; and performing a weighted addition of the charging rate detected by the integrating method and the charging rate detected by the voltage method in accordance with the charging rate of the secondary battery, whereby detecting a final charging rate.

Abstract: A method of changing a secondary battery, a method of calculating a remaining capacity rate of the secondary battery, and a battery pack are provided. The method of charging a secondary battery includes the steps of: performing a detection of a charging rate of the secondary battery using an integrating method in which a battery capacity is calculated by integrating a current value or a power value of the secondary battery for a certain period of time, and a detection of the charging rate of the secondary battery using a voltage method in which a voltage value of the secondary battery is measured and the charging rate is calculated based on a correlation between the voltage value and the charging rate; and performing a weighted addition of the charging rate detected by the integrating method and the charging rate detected by the voltage method in accordance with the charging rate of the secondary battery, whereby detecting a final charging rate.

Abstract: A remaining capacity calculation method for a secondary battery and a battery pack are provided. Dischargeable electric power is accurately calculated and accuracy of a remaining capacity rate found by an electric power integration method may be improved by providing a remaining capacity calculation method for a secondary battery. The method includes calculating a consumed electric power by way of integration of voltage and current measured at a preset time interval when using the secondary battery; calculating an available dischargeable electric power by subtracting an energy loss and unavailable energy from a discharge electric power of the secondary battery; and calculating a remaining capacity rate from a ratio between the calculated electric power and the dischargeable electric power.

Abstract: A secondary cell residual capacity calculation method and a battery pack capable of calculating the secondary cell residual capacity is provided. The calculation method includes detecting a temperature of a plurality of secondary cells; detecting a current and a terminal voltage of the plurality of secondary cells; digitizing temperature, current, and terminal voltage; calculating a cell polarization voltage from the digitized temperature, current and terminal voltage; calculating an original cell voltage from both of the calculated cell polarization voltage and the detected terminal voltage; and calculating a residual capacity rate based on the calculated original cell voltage with reference to a prearranged residual capacity reference data table.

Abstract: A battery pack mounted to a predetermined apparatus to permit supply and output of power of a secondary battery cell between the battery pack and the apparatus, comprising: a plurality of field effect transistors for stopping charge or discharge current in response to a control signal; and a control circuit for controlling the charge or discharge current of the secondary battery cell by outputting control voltage for controlling the field effect transistors; wherein the control voltage is supplied to the respective gates of the plurality of field effect transistors through resistors of 10 [k&OHgr;] or more.

Abstract: A battery pack mounted to a predetermined apparatus to permit supply and output of power of a secondary battery cell between the battery pack and the apparatus, comprising: a plurality of field effect transistors for stopping charge or discharge current in response to a control signal; and a control circuit for controlling the charge or discharge current of the secondary battery cell by outputting control voltage for controlling the field effect transistors; wherein the control voltage is supplied to the respective gates of the plurality of field effect transistors through resistors of 10 [k&OHgr;] or more.