Battery charger

• US 5,606,240 A
• Filed: 09/19/1995
• Issued: 02/25/1997
• Est. Priority Date: 07/21/1992
• Status: Expired due to Fees

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Kokuga, Toshiharu, Okada, Tetsuya, Tamai, Mikitaka
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): Ponomarenko, Nicholas
• Application Number:
  US08/530,439
• Time in Patent Office: 525 Days
• Field of Search: 320/5, 320/14, 320/22, 320/32
• US Class Current: 320/129
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: H02J 7/007182 in response to battery voltage

Abstract

A battery charger has a battery capacity detector for detecting the remaining battery capacity and a timer setter for controlling the timer setting that determines the battery charging time based on the results from the battery capacity detector. The battery capacity detector measures the battery voltage, the battery constant current charging time, or the battery capacity. The timer includes a protection timer to forcibly end battery charging and a constant current charging timer to establish the constant current charging interval.

Claims

1. A battery charger for charging a battery, said charger comprising:

a power source for supplying a charging current to the battery;

a charging state detector connected to the battery for detecting a charging state of the battery;

a timer connected to said charging state detector for setting a charging time according to a detection results of said charging state detector; and

a controller connected to said power source for controlling said charging current supplied from said power source to the battery according to said charging time determined by said timer;

wherein said controller temporarily halts charging of the battery and applies a load to the battery and wherein said charging state detector comprises a voltage detector for detecting a battery voltage drop of the battery under load when battery charging is temporarily halted by said controller and a computation circuit for computing said charging state of the battery in response to said detected voltage drop of said voltage detector.

2. A battery charger for charging a battery, said charger comprising:

a power source for supplying a charging current to the battery;

a charging state detector connected to the battery for detecting a charging state of the battery;

a timer connected to said charging state detector for setting a charging time according to a detection results of said charging state detector; and

a controller connected to said power source for controlling said charging current supplied from said power source to the battery according to said charging time determined by said timer;

wherein said controller temporarily halts charging of the battery and effects a temporary pulse discharge of the battery and wherein said charging state detector comprises a voltage detector for detecting a battery voltage drop during a temporary pulse discharge of the battery effected by said controller and a computation circuit for computing said charging state of the battery in response to said detected voltage drop from said voltage detector.

3. A battery charger for charging a battery, said charger comprising:

a power source for supplying a charging current to the battery;

said power source being in one of a constant current charging mode and a quasi-constant current charging mode until a battery voltage of the battery reaches a prescribed voltage and then being in a constant voltage charging mode;

a charging state detector connected to the battery for detecting a charging state of the battery;

a timer connected to the charging states detector for setting a charging time according to a detection results of said charging state detector; and

a controller connected to said power source for controlling said charging current supplied from said power source to the battery according to said charging time determined by said timer;

wherein said charging state detector comprises a computation circuit for detecting said charging time of the battery in both said constant current charging mode and said quasi-constant current charging mode and for computing said charging state of the battery in response thereto.

4. A battery charger for charging a battery, said charger comprising:

a power source for supplying a charging current to the battery;

said power source being in one of a constant current charging mode and a quasi-constant current charging mode until a battery voltage of the battery reaches a prescribed voltage and then being in a constant voltage charging mode;

a charging state detector connected to the battery for detecting a charging state of the battery;

a timer connected to the charging states detector for setting a charging time according to a detection results of said charging state detector; and

a controller connected to said power source for controlling said charging current supplied from said power source to the battery according to said charging time determined by said timer;

wherein said controller temporarily halts charging of the battery and applies a load to the battery and wherein said charging state detector comprises a voltage detector for detecting a battery voltage drop of the battery under load when battery charging is temporarily halted by said controller and a computation circuit for computing said charging state of the battery in response to said detected voltage drop of said voltage detector.

5. A battery charger for charging a battery, said charger comprising:

a power source for supplying a charging current to the battery;

said power source being in one of a constant current charging mode and a quasi-constant current charging mode until a battery voltage of the battery reaches a prescribed voltage and then being in a constant voltage charging mode;

a charging state detector connected to the battery for detecting a charging state of the battery;

a timer connected to the charging states detector for setting a charging time according to a detection results of said charging state detector; and

a controller connected to said power source for controlling said charging current supplied from said power source to the battery according to said charging time determined by said timer;

wherein said controller temporarily halts charging of the battery and effects a temporary pulse discharge of the battery and wherein said charging state detector comprises a voltage detector for detecting a battery voltage drop for a temporary pulse discharge of the battery effected by said controller and a computation circuit for computing said charging state of the battery in response to said detected voltage drop of said voltage detector.