Battery state monitoring apparatus

• US 4,947,123 A
• Filed: 11/23/1988
• Issued: 08/07/1990
• Est. Priority Date: 11/30/1987
• Status: Expired due to Fees

• Current Assignee: Aisin AW Company Limited (Aisin Corp.), Kabushiki Kaisha Shinsangyokaihatsu
• Original Assignee: Aisin AW Company Limited (Aisin Corp.), Kabushiki Kaisha Shinsangyokaihatsu
• Inventors: Minezawa, Yukihiro
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Mueller, Robert W.
• Application Number:
  US07/274,569
• Time in Patent Office: 622 Days
• Field of Search: 324/426, 324/427, 324/428, 324/431, 324/430, 340/636, 320/48
• US Class Current: 324/427
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements

Abstract

A battery state monitoring apparatus determines the remaining life of a battery, which is used by being repeatedly charged and discharged, upon taking into account the charging/discharging characteristic of the battery and the surrounding temperature, thereby making it possible to ascertain the remaining life of the battery in accurate fashion. The apparatus includes a voltage measuring unit for measuring terminal voltage of a battery, a current measuring unit for measuring charging and discharging current of the battery, a temperature measuring unit for measuring temperature of the battery, an arithmetic unit to which measurement values outputted by the voltage measuring unit, current measuring unit and temperature measuring unit are applied for computing remaining life of the battery, and a remaining life display unit for displaying the remaining life of the battery computed by the arithmetic unit. Thus, the terminal voltage, charging and discharging current and the temperature of the battery are measured by the voltage measuring unit, current measuring unit and temperature measuring unit, and signals indicative of the measurement values are inputted to the arithmetic unit. Upon receiving these values, the arithmetic unit computes the remaining life of the battery and causes the results to be displayed on the display unit.

Claims

1. A battery state monitoring apparatus comprising:

voltage measuring means for measuring terminal voltage of a battery;

current measuring means for measuring charging and discharging current of said battery;

temperature measuring means for measuring temperature of said battery;

arithmetic means for receiving measurement values outputted by said voltage measuring means, said current measuring means and said temperature measuring means and for computing remaining battery life;

said arithmetic means for performing a temperature correction including adder circuit means for increasing said computed remaining battery life based on said temperature correction when said battery is in a charging state; and

remaining life display means for displaying said computed remaining battery life computed by said arithmetic means.

2. The battery state monitoring apparatus of claim 1, wherein said arithmetic means includes charging discharging detector means for detecting charging and discharging states of said battery, and subtracting means for decreasing said computed remaining battery life based upon said temperature correction when said battery is in a discharging state.

3. The battery state monitoring apparatus of claim 2, wherein said arithmetic means includes changeover circuit means for changing between said adder circuit means and said subtracting circuit means in accordance with an output of said charging discharging detector means.

4. The battery state monitoring apparatus of claim 2, wherein said arithmetic means includes memory means having a data map containing initial values of remaining battery life.

5. The battery state monitoring apparatus of claim 2, wherein said arithmetic means includes memory means having a data map containing additive values and said adder circuit means increases said computing remaining battery life based on said additive values.

6. The battery state monitoring apparatus of claim 2, wherein said arithmetic means includes memory means having a data map containing subtractive values and said subtracting circuit means decreases said computed remaining battery life based on said subtractive values.

7. The battery state monitoring apparatus of claim 1, wherein said display is a digital display.

8. A battery state monitoring apparatus comprising:

voltage measuring means for measuring terminal voltage of a battery;

current measuring means for measuring charging and discharging current of said battery;

temperature measuring means for measuring temperature of said battery;

arithmetic means for receiving measurement values outputted by said voltage measuring means, said current measuring means and said temperature measuring means and for computing remaining battery life;

said arithmetic means including adder circuit means for increasing said computed battery life when said battery is in a charging state, memory means having a data map containing temperature correcting values, and correcting unit means for correcting an amount of said increasing of said computed remaining battery life based on said temperature correcting values.