Method and apparatus for displaying a residual electric charge of a battery for an electrically driven vehicle

• US 5,352,982 A
• Filed: 09/30/1991
• Issued: 10/04/1994
• Est. Priority Date: 10/16/1990
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Suzuki, Hiroyuki, Honda, Satoshi, Nakazawa, Yoshihiro, Sasaki, Shigemi
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): Braun, Glenn W.
• Application Number:
  US07/767,650
• Time in Patent Office: 1,100 Days
• Field of Search: 324/427, 324/431, 324/433, 320/48, 340/636, 364/483
• US Class Current: 324/427
• CPC Class Codes: B60L 1/14 to electric lighting circuits
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 2250/16 by display
• CPC Class Codes: B60L 2260/54 Energy consumption estimation
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• 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 31/3828 using current integration
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y10S 320/19 : Charger status, e.g. voltmeter

Abstract

In a method and apparatus for displaying a residual electric charge for a battery of an electrically driven vehicle, the battery'"'"'s capacity is detected after the battery is charged. This information is utilized by a residual electric charge meter to indicate a fully charged state of the battery. As the battery begins to supply current to the electric loads, dissipated power is calculated from the product of the value of the current and the length of time during which the current has been supplied. This calculated dissipated power is subtracted from the fully charged capacity from time to time in order to derive the residual electric charge. The battery residual electric charge meter is driven in accordance with the derived value to indicate a current residual electric charge. As such, the battery residual electric charge meter displays values which depend upon the actual fully charged capacity and a residual charge.

Claims

1. An apparatus for determining a residual electric charge of a battery for an electrically driven vehicle comprising:

measuring means for initially measuring a charge capacity of the battery after completion of a charging operation;

calculation means for calculating power dissipated by the battery;

control means, operatively connected to said measuring means and said calculation means, for determining a residual electric charge of the battery from a difference between the measured charge capacity and the calculated dissipated power; and

display means, operatively connected to said control means, for displaying said residual electric charge of the battery,

said control means comparing said residual electric charge to a predetermined lower limit and disabling power supply from the battery to the electrically driven vehicle when said residual electric charge is lower than said predetermined lower limit.