Toshiba Battery Co., Ltd.

Sanyo Electric Co., Ltd.

Nobuo Shiojima

Sadakazu Enomoto

Hirotaka Sakai

Yukinori Akamoto

Hideki Miyamoto

Yasushi Mori

Kiyoshi Ishitsuka

Yoshinao Sano

An uninterruptible power supply device has a power supply circuit for supplying power from a power source to electronic equipment, a power interruption detection section for detecting interruption of the power supply from the power source, and a rechargeable battery charged by the power source. The uninterruptible power supply device further includes control means for controlling charging of the rechargeable battery in accordance with a charge state of the battery and also controlling the power supply from the rechargeable battery to the electronic equipment, and timer means for stopping the power supply to the control means after a lapse of a fixed time period from generation of a power interruption signal or shut-down signal, whereby wasteful consumption of electric energy stored in the rechargeable battery can be suppressed and also charge control for the rechargeable battery can be smoothly restarted at the recovery from power outage or at the start of the device.

Uninterruptible power supply device

An uninterruptible power supply comprises a power supply unit for generating DC power at a predetermined voltage from AC power supplied from the outside to supply the DC power to an electronic device, and a rechargeable battery unit including rechargeable battery cells for storing the power supplied thereto from the power supply unit for supplying the electronic device with the power stored in the rechargeable battery upon service interruption of the AC power. Particularly, the rechargeable battery unit comprises a battery state monitoring unit for monitoring a state of the rechargeable battery cells, and communicating means for notifying the electronic device of information indicative of the state of the rechargeable battery detected by the battery state monitoring unit, thereby securely guaranteeing the operation of the electronic device upon power failure, and sufficiently improve the operational reliability of the entire system.

Uninterruptible power supply

An uninterruptible power supply includes a power supply unit for generating DC power at a predetermined voltage from AC power supplied from the outside to supply the DC power to an electronic device, and a rechargeable battery unit including rechargeable battery cells for storing the power supplied thereto from the power supply unit for supplying the electronic device with the power stored in the rechargeable battery upon service interruption of the AC power. The rechargeable battery unit includes a battery state monitoring unit for monitoring a state of the rechargeable battery cells and a communicating unit for notifying the electronic device of information indicative of the state of the rechargeable battery detected by the battery state monitoring unit. The rechargeable battery cells include nickel-metal hydride rechargeable batteries.

A rechargeable battery device includes battery voltage detection means which detects the terminal voltage of a rechargeable battery comprising a nickel hydride metal battery and switching means which switches on and off the charging current of the rechargeable battery continuously or intermittently. A value corresponding to the internal resistance R of the rechargeable battery is determined from the battery voltage Von immediately before the charging current is switched off and the open battery voltage Voff after the charging current is switched off. The value Z(int) corresponding to the early-stage internal resistance R of the rechargeable battery and the value Z(now) corresponding to the latest internal resistance R of the rechargeable battery are compared to determine the operation life of the rechargeable battery.

Rechargeable battery device equipped with life determination function

A rechargeable battery pack has a battery voltage detector, a full charge detecting circuit detecting a full charge state, a switch interposed in a charge current circuit that opens the charge current circuit when detecting a fall charge state, a memory for storing a closed circuit voltage immediately before the charge current circuit is opened, an internal resistance detection circuit for finding a value corresponding to an internal resistance of the rechargeable battery cell from an open circuit voltage and the closed circuit voltage stored in the memory after the charge current circuit is opened, and a lifetime indicator to predict lifetime. This enables accurate determination of the lifetime of the rechargeable battery cell under stable conditions without wastefully consuming the charging capacity.

Rechargeable battery pack

A secondary battery apparatus includes a secondary battery, a battery voltage detector, a temperature rising rate detector and a charge controller. The charge controller starts pulse charging of the secondary battery which is performed by turning on/off a switch element located in a charge path of the secondary battery at predetermined periods when a terminal voltage of the secondary battery exceeds a first set voltage during charging of the secondary battery, stops the pulse charging while maintaining the switch element in a conductive state after the time the terminal voltage, observed at a particular time within a switch element blocking period during the pulse charging, exceeds a second set voltage, and blocks the switch element to stop charging the secondary battery when the temperature rising rate detector detects the secondary battery having reached a fully charged state during the charging subsequent to the pulse charging. As a result, the secondary battery is reliably and efficiently charged to the fully charged state in a short time without being affected by fluctuations in a charge current or an ambient temperature.

Secondary battery apparatus

A correction device for secondary batteries comprises a voltage difference detection circuit for detecting variation in terminal voltages of at least two secondary batteries connected in series, and a discharge circuit for discharging one of the at least two secondary batteries which has a maximum terminal voltage, when the variation in the terminal voltages exceeds a preset value. The discharge circuit stops discharging when the terminal voltage of the one of the secondary batteries which is discharged becomes lower than a reference value.

Correction device and correction method for secondary batteries

A secondary battery charging circuit of this invention includes a charging source for supplying a charging current to a secondary battery, a temperature detection unit for generating an output which changes almost linearly with respect to a change in temperature of the secondary battery during a charging operation, a differential unit for obtaining a differential value of an output from the temperature detection unit, a comparator unit for comparing the differential value during the charging operation with a setting value, and for, when the relationship between the two values is reversed, generating an inverted output, a timer circuit unit, started simultaneously with start of the charging operation of the secondary battery, for generating a timer output after an elapse of a predetermined period of time, and a charge control unit for controlling the charging operation of the secondary battery in response to one, generated earlier, of the inverted output from the comparator unit, and the timer output from the timer circuit unit.

Secondary battery charging circuit

A reference voltage generating circuit generates a reference voltage Vz, which is a predetermined level different from the potential of one of the terminals of a secondary battery. A minute voltage change extracting circuit comprises a operational amplifier to which the reference voltage Vz is input, a capacitor C, and a resistor R. The minute voltage change extracting circuit extracts minute voltage changes, which appear in the last stage of a process of charging the secondary battery and have components of a frequency higher than a change in a terminal voltage corresponding to the amount of charge, as output signals which vary around the reference voltage Vz. The output signals are shaped into pulse signals by a shaping circuit. The pulse signals are counted by a counter circuit. When the count reaches a predetermined value, charging of the secondary battery is controlled.

Growing community of inventors

Tokyo, Japan

Nobuo Shiojima