Sanyo Electric Co., Ltd.

Takahiro Yamashita

Tetsuya Okada

Eiji Satsuma

Akio Furukawa

Yasushi Kuroda

Hisashi Kameyama

Tomoya Fukuda

Tatehito Yagi

Naoki Kawai

Tetsuya Kawasaki

Yoshikazu Izumi

A protection circuit for a battery includes a discharge FET, a control circuit, a first small-signal FET, and a second small-signal FET. The discharge FET connected in series to a battery interrupts an electric current. The control circuit switches on or off the discharge FET. The first small-signal FET connected in parallel between a gate (G) and a source (S) of the discharge FET is switched to an ON state, to set a gate voltage of the discharge FET to an OFF-state voltage. The second small-signal FET connected in parallel between G and S of the discharge FET detects a voltage between a drain (D) and S of the discharge FET. When the voltage between D and S of the discharge FET exceeds a preset voltage, the second small-signal FET is switched to an ON state to set the gate voltage of the discharge FET to the OFF-state voltage.

Protection circuit for battery and power supply device provided with said protection circuit

The method of data transmission embedded in electric power transmission disposes a transmitting coiland a receiving coilin close proximity, transmits electric power in a non-contact fashion from the transmitting coilto the receiving coilby magnetic induction, and transmits data from the receiving coilside to the transmitting coilside. The method of data transmission changes the load on the receiving coiland detects transmitting coilcurrent change corresponding to that load variation to send data from the receiving coilside to the transmitting coilside.

Method of data transmission embedded in electric power transmission and a charging stand and battery device using transmitting coil current change to receive that data transmission

A method for charging a rechargeable battery by using a charge power supply that charges the rechargeable battery at constant voltage is provided. A pulse charge operation is performed at a charge process start. The charge process is stopped when current in the pulse charge operation is not greater than a predetermined value and it is determined that the rechargeable battery is in a full-charge state. On the other hand, the rechargeable battery is charged at constant voltage when the current in the pulse charge operation is greater than the predetermined value.

Method for charging rechargeable battery

A battery charging apparatus having a plurality of charging units connected in series. A charging unit has a series switch connected in series with a rechargeable battery, and a parallel switch connected in parallel with the series connected rechargeable battery and series switch. A charging control section controls charging of a rechargeable battery by switching the series switch and parallel switch ON and OFF. The charging control section changes the duty factor for switching series switches and parallel switches ON and OFF, switches a charging unit between a charging mode and a cut-off mode at a prescribed duty factor, and controls rechargeable battery charging currents to charge a plurality of batteries.

Battery charging apparatus for charging a plurality of batteries

The battery charging detects battery temperature and includes a temperature maintaining charging operation wherein average charging current is controlled to drive battery temperature to a holding temperature, and charging is performed while maintaining battery temperature at that holding temperature. In addition, a temperature increasing charging operation occurs prior to the temperature maintaining charging operation. The battery is charged with a current which raises battery temperature until the holding temperature is reached. When battery temperature rises to the holding temperature in the temperature increasing charging operation, charging can transition to the temperature maintaining charging operation.

Battery charging method

A battery charger for charging a plurality of rechargeable batteries and is provided with temperature sensors for detecting battery temperature. The battery charger compares the battery temperature detected by the temperature sensors and charging stop temperature, and stops charging when the detected temperature becomes greater than the charging stop temperature. The battery charger has a plurality of attachment detecting portions for detecting attachment of the batteries respectively and independently. The number of temperature sensors is less than the maximum number of the batteries that can be attached. The battery charger varies the charging stop temperature for stopping charging in accordance with the battery-attached positions detected by the attachment detecting portions.

Battery charge having a plurality of channels

In the invention, a plurality of batteries are connected in parallel with each other and are charged, and &minus;&Dgr;V of a drop of a battery voltage from a peak voltage is detected to judge full charge, and currents flowing to the batteries connected in parallel are detected in the state where charging is stopped by the drop of &minus;&Dgr;V. When the currents flowing to all the batteries are larger than a set current in the state where charging is stopped, it is judged that full charge is not attained and charging is resumed, and when the currents are smaller than the set current, it is judged that all the batteries are fully charged.

Charging method and charger

In the method of fast-charging of a rechargeable battery, full-charge state is determined on the basis of a peak battery voltage or a decrease &Dgr;V in the battery voltage after the peak voltage. At the beginning of the fast-charge process, an initial battery voltage is measured. In case where the initial voltage is higher than a preselected voltage, the battery is fast-charged with a normal fast-charge current. In case where the initial voltage is lower than the preselected voltage, the battery is fast-charged with a restricted fast-charge current that is weaker than the fast-charge current.

Method of fast-charging of a rechargeable battery

This method to determine remaining capacity of a rechargeable battery calculates remaining battery capacity by subtracting discharge capacity, computed by integrating battery discharge current, from charge capacity. Voltage of the discharging rechargeable battery is measured, and when battery voltage reaches a first voltage and a lower second voltage, the computed remaining battery capacity is corrected according to a previously established first remaining battery capacity and second remaining battery capacity corresponding to those voltages. The difference between calculated remaining battery capacity or discharge capacity at the first and second voltages is compared to the difference between the previously established first and second remaining battery capacity values, and the first voltage is modified to make those two differences equal.

Method to determine remaining capacity of a rechargeable battery

A battery discharging apparatus is provided with a battery discharger and a controller. The controller is connected to a battery voltage sensor and a timer, a current sensor and a discharge switch, or a current sensor and a battery power capacity sensor. The controller directs the discharger to recover battery capacity lost due to the memory effect using a deep memory effect eliminating discharge.

Battery discharging apparatus

A battery discharging apparatus is provided with a battery discharger and a control unit. The control unit is provided with a current sensor and a battery power capacity sensor. The control unit directs the discharger to recover battery capacity lost due to memory effect using a deep memory effect eliminating discharge.

Growing community of inventors

Sumoto, Japan

Takahiro Yamashita