Sanyo Electric Co., Ltd.

Takayuki Mino

Toshiharu Kokuga

Shoichi Toya

Eiji Satsuma

Hideyo Morita

A secondary battery is connected to a protecting circuit. The protecting circuit interrupts charging of the secondary battery when the battery voltage of the secondary battery reaches a first protecting voltage which is higher than a first voltage, the first voltage being the full charge voltage of the secondary battery. After constant current charging of the secondary battery, the secondary battery is charged until the battery voltage of the secondary battery becomes higher than the first protecting voltage for achieving rapid charging of the secondary battery. When the secondary battery is charged in this condition, the protecting voltage of the protecting circuit is changed over to a second protecting voltage which is higher than the first protecting voltage for this preventing the protecting circuit from operating.

Secondary battery charging method and apparatus which controls

The power supply apparatus of this invention has a portable case. The case is provided with battery attachment sections for attaching a plurality of battery packs containing rechargeable batteries, a charging circuit for charging battery packs, a charging power input section for supplying power to the charging circuit for battery pack charging, a discharge circuit for discharging battery packs to electrical equipment loads, and a discharge power output section for delivering output from the discharge circuit to external loads.

Power supply apparatus to provide power to electrical equipment from a

A charging apparatus charges a secondary battery, while controlling an output voltage of the charging apparatus to maintain the effective charging voltage at a substantially constant predetermined value at which the secondary battery is actually charged. Such a method prevents the secondary battery from being overcharged with a overvoltage, and enables the charging time to be short.

Method of charging a secondary battery

A temperature sensor avoids battery charger over-heating when rechargeable batteries arc charged In succession. The battery charger is provided with a control means having a voltage detection section and a control circuit. The control circuit stops charging when a rechargeable battery reaches full charge. The control means also has a temperature sensor to determine the temperature of heat producing elements in the power supply circuit. Charging current is reduced when the temperature of heat generating elements exceeds a specified temperature. Full charge detection is suspended when charging current is reduced to avoid false detection.

Battery charger having a temperature sensor and a rechargeable battery

By sensing battery voltage and temperature, a battery charger fully charges a battery even when a load is attached during charging. A control circuit suspends charging by detecting a change in battery voltage near a peak voltage. A charge restart section restarts charging depending on computations performed on the output from a temperature detection section. After charging is stopped, it is restarted if battery temperature is less than a set value, or if the rate of battery temperature rise is less than a set rate.

Battery charger which suspends charging according to a voltage drop and

A residual capacity displaying device which discriminates whether or not a battery is deteriorated, and display the result of the discrimination. The residual capacity displaying device for a battery pack includes a current detecting unit for detecting current flowing to and from a battery pack. A battery identifying unit identifies the kind of the battery pack, and an arithmetic unit calculates the capacity of the battery pack according to the output of the current detecting unit and the time thereof. The dischargeable capacity of the battery pack is stored according to the output of the battery identifying unit. Also, the capacity of the battery pack which is discharged is compared until the voltage of the battery pack reaches a predetermined voltage value with the dischargeable capacity. When the result of comparison reaches a predetermined value, LEDs display the fact that the battery pack has been deteriorated.

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Mihara-gun, Japan

Takayuki Mino