An electricity storage device includes a plurality of cell batteries C.sub.1 to C.sub.M serially connected; and a management module including a balance circuit that can selectively cause electricity to be discharged from each of the plurality of cell batteries, and a controller. The controller includes a current-voltage acquiring unit that acquires a charging current and the respective voltages of the plurality of cell batteries and a balance control unit that, if a determination condition and an execution condition are satisfied, determines a lowest-voltage cell battery having a lowest voltage among the plurality of cell batteries and controls the balance circuit such that electricity is discharged from the plurality of cell batteries other than the lowest-voltage cell battery for time periods in accordance with differences between the lowest voltage and the respective voltages of the cell batteries when the determination condition and the execution condition are satisfied.

An embodiment of the invention provides a method for reducing data corruption in a wireless power transmission system. Power is transmitted from a primary coil to a secondary coil by induction. The voltage induced on the secondary coil by induction is rectified. The change in current supplied to a load configured to be coupled to the wireless power transmission system is limited.

A battery pack and charger platform including a voltage coupling circuit comprising an input that receives an input voltage and an output that sends an output voltage, a voltage monitoring circuit having an input coupled to the voltage coupling circuit output and an output, and a power source having an input coupled to the voltage monitoring circuit output, the power source input receives an input voltage representative of a charge instruction.

Processing circuitry functionally includes: an internal resistance calculation unit; a reference value obtaining unit configured to obtain a reference value for internal resistance; a correction coefficient calculation unit configured to calculate a correction coefficient indicating how great difference between the internal resistance and the reference value is: a correction value calculation unit configured to calculate a correction value by correcting the reference value using the correction coefficient; and an estimation unit configured to calculate estimated internal resistance, based on the correction value and present voltage. The processing circuitry is configured to control charge and/or discharge of the battery, based on the internal resistance or the estimated internal resistance. The correction value calculation unit is configured to calculate the correction value by correcting the reference value using the correction coefficient calculated in the past when the internal resistance calculation unit is unable to calculate the internal resistance.

An electronic device includes a display, a conductive coil, a wireless charging circuit electrically connected to the conductive coil, a power management circuit, a battery; and a processor, wherein the processor may be configured to control the electronic device to: measure a current flowing from the power management circuit to the wireless charging circuit while power is transferred to an external device through the conductive coil, and adjust the power transferred to the external device through the conductive coil based on a part of a power amount preset in a signal requesting addition of power based on a value of the current being between a first threshold value and a second threshold value greater than the first threshold value.

A surface cleaning apparatus, such as a portable surface cleaning apparatus is powered by one or more ultracapacitors and a charging unit for same is provided.

A charge-discharge unit includes a discharge circuit, a charge-discharge circuit, wires respectively connecting the discharge circuit and the charge-discharge circuit to a load, and a unit controller to control the discharge circuit and the charge-discharge circuit. The unit controller is configured or programmed to control the discharge circuit and the charge-discharge circuit in a first mode or a second mode. In the first mode, the discharge circuit and the charge-discharge circuit are controlled such that the discharge circuit outputs to the load a current greater than zero, and the charge-discharge circuit outputs to a battery a current greater than zero. In the second mode, the discharge circuit is controlled to output to the load a current of a value greater than zero, and the charge-discharge circuit is caused to perform a charge termination operation of stopping the current outputted to the battery.

A vehicle electricity storage system includes a control device including: a calculation unit configured to calculate an internal resistance value of the battery based on the voltage value and the current value; a derivation unit configured to derive an estimated internal resistance value, which is an estimated value of the current internal resistance of the battery, based on the calculated internal resistance value calculated and the current voltage value; and a setting unit configured to set a charging electricity upper limit value, which is an upper limit value of charging electricity for charging the battery, based on the derived estimated internal resistance value, the current voltage value, and a current value at present. The derivation unit is configured to derive a greater value as the estimated internal resistance value, as a difference between an upper limit voltage value of the battery and the current voltage value becomes smaller.

A battery charging method based on lithium plating detection includes: acquiring a battery charging strategy table after receiving a battery charging instruction; charging a battery according to a charging current in the battery charging strategy table, and performing at least one charging lithium plating detection on the battery during the charging of the battery, to obtain a first lithium plating detection result; continuing the charging of the battery according to the charging current and the charging lithium plating detection of the battery when no lithium plating phenomenon occurs, and stopping the charging lithium plating detection when the lithium plating phenomenon occurs or the charging of the battery is completed; and updating the charging current according to a preset first current reduction strategy when the lithium plating phenomenon occurs, and continuing the charging of the battery according to the updated charging current until the charging is completed.

There is provided a battery system including: a controller; a main switch controlled by the controller to supply or cut off a voltage of a battery to a load; and a semiconductor pre-charger module including a semiconductor switch connected in parallel with the main switch and configured to supply or cut off the voltage of the battery to the load according to a control signal output from the controller, and a semiconductor switch driver configured to receive the control signal from the controller and output a single pulse signal for driving the semiconductor switch to turn on and off the semiconductor switch. Here, the semiconductor switch driver of the semiconductor pre-charger module includes an isolation element configured to electrically isolate the controller and the battery voltage, and the semiconductor switch of the semiconductor pre-charger module is a MOS-controlled thyristor (MCT).