US 5,717,311 AGranted

Fast-charging device for rechargeable batteries

AssigneeSamsung Electronics Co., Ltd.

InventorsSang-Tae Im, Hwan-Ho Seoung, Byung-Cho Choi

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Abstract

A battery charging device for providing a fast charging a rechargeable battery and controlling the charging process to prevent overcharging. The battery charging device detects a decrease in the voltage of the rechargeable battery as it is being charged and approaches a full charge, and modulates the switching of a switching power supply supplying current to the rechargeable battery in response thereto. The battery charging device has a first resistor in series with the rechargeable battery which is to be charged, a power supply which charges the rechargeable battery, a charging control unit which detects a decrease in the voltage across the rechargeable battery using capacitors and which outputs battery condition signals and battery error signals in response thereto, and a power supply control unit which accepts a mode change signal and a battery error signal from the charging control unit and outputs a control signals for controlling the power supply.

Claims13

Dependent claims

A battery charging device, comprising:

a first resistor connected in series with a rechargeable battery to be charged;
a power supply connected to supply electrical current through said series connection of said first resistor and said rechargeable battery;
charging control means, connected to said rechargeable battery and said first resistor, for detecting a decrease in a voltage across said rechargeable battery and outputting a battery condition signal indicating that said voltage across said rechargeable battery has decreased, wherein said charging control means comprises:
a first capacitor having a negative electrode connected to a negative electrode of said rechargeable battery;
a second resistor connected in series with said first capacitor;
a first operation amplifier having a negative input terminal connected in series with said series connection of said first capacitor and said second resistor, and having a positive input terminal connected to a positive electrode of said rechargeable battery;
a diode having a cathode connected to an output terminal of said first operation amplifier and having an anode connected to said negative input terminal of said first operation amplifier;
a second capacitor connected in parallel with said diode;
a second operation amplifier having a positive input terminal connected to said positive input terminal of said first operation amplifier, and having a negative input terminal connected to an output terminal of said second operational amplifier;
and
a first comparator having a positive input terminal connected to said output terminal of said first operation amplifier, and having a negative input terminal connected to said output terminal of said second operation amplifier;
and
power supply control means for controlling said power supply in accordance with said battery condition signal.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/639,088Filed 24 Apr 1996
Priority: KR 95-962124 Apr 1995
Granted: 10 Feb 1998
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

H01M 10/46
Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells: accumulators structurally combined with charging…
H02J 7/02
Circuit arrangements for charging or discharging batteries or for supplying loads from batteries: for charging batteries from AC mains by converters
H02J 7/963
In response to battery voltage: in response to battery voltage gradient
H01M 10/345
Gastight accumulators: gastight metal hydride accumulators