Battery charger with cell failure warning circuit

Assignee: NEC Corp

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Filing: 1991-12-02

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Granted: —

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Expires: 2011-12-02

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Abstract

Abstract In a battery charger, a barging current is supplied to a rechargeable battery and a load current to a load circuit from a DC voltage source during a charging mode and the battery is allowed to supply a load current to the load circuit during a subsequent discharging mode. The battery voltage is compared with a reference voltage for detecting a low voltage condition, whereupon a counter is triggered and a warning signal is generated if the low voltage condition continues for an interval longer than a specified value. According to a second embodiment, the battery voltage is compared with low and high reference voltages and a first comparison signal is generated when it is lower than the former and a second comparison signal is generated when it is higher than the latter. The high reference voltage is set equal to a value which is lower than a voltage to which the battery can be charged during a normal condition, but higher than a maximum voltage to which it can be charged during an abnormal condition. A warning signal is generated if the first comparison signal is not followed by the second comparison signal.

Inventors

👤 Takeshi c/o NEC Engineering Ltd. Yokogawa

Bibliographic Details

Application Number —

Jurisdiction EP

Data Source google_patents

Last Synchronized 2026-11-08 11:26

CPC Classifications

H; H02; H02J; H02J7/00; H02J7/80

Claims Analysis

Total Claims: 2

Claim 1

Independent Claim 116 words

A battery charger for charging a multi-cell rechargeable battery, comprising: means for periodically operating the charger in a charging mode in which a DC voltage source supplies a charging current to said battery and a load current to load means and in a discharging mode in which said battery is allowed to supply a load current to said load means; comparator means for comparing a battery voltage of said rechargeable battery with a reference voltage and producing an output signal when the battery voltage is lower than the reference voltage; and counter means for generating a warning signal when a time interval of the output signal of said comparator means is longer than a specified interval.

Claim 2

Dependent Claim 176 words

A battery charger for charging a multi-cell rechargeable battery, comprising: means for supplying from a DC voltage source a charging current to said battery and a load current to load means during a charging mode and allowing said battery to supply a load current to said load means during a discharging mode instead of from said DC voltage source; comparator means for comparing a battery voltage of said rechargeable battery with a low reference voltage and producing a first output signal when the battery voltage is lower than the low reference voltage and for comparing the battery voltage with a high reference voltage and procducing a second output signal when the battery voltage is higher than the high reference voltage, said high reference voltage being lower than a voltage to which said battery can be charged during a normal condition but higher than a voltage to which said battery ran be charged during an abnormal condition; and means for generating a warning signal when said first output signal is not followed by said second output signal.

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