Method for indicating battery capacity

• US 5,166,623 A
• Filed: 03/04/1991
• Issued: 11/24/1992
• Est. Priority Date: 03/04/1991
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Ganio, Christopher
• Primary Examiner(s): Harvey, Jack B.
• Assistant Examiner(s): BROWN, GLENN WARNER
• Application Number:
  US07/664,141
• Time in Patent Office: 631 Days
• Field of Search: 324/426, 324/427, 324/428, 324/433, 340/636, 320/48, 320/31, 320/32, 320/40, 320/39
• 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 31/3835 involving only voltage measurements
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

Battery capacity in a portable two-way radio is determined by measuring the voltage across the battery at predetermined time intervals and determining battery voltage slopes. Each battery voltage slope is compared with a previously determined battery voltage slope and the battery capacity is determined by analyzing the changing pattern of the battery voltage slopes.

Claims

1. A method for determining battery capacity comprising the steps of:

measuring battery voltages at predetermined time intervals;

determining battery voltage slopes by comparing each battery voltage with a previously measured battery voltage;

continuously comparing each battery voltage slope with a previously determined battery voltage slope;

indicating a substantially full battery capacity if said battery voltage slopes are substantially decreasing;

indicating a substantially intermediate battery capacity if said battery voltage slopes are substantially constant; and

indicating a substantially empty battery capacity if said battery voltage slopes are substantially increasing.

2. In a battery having a capacity characteristic separated into a full capacity region, an intermediate capacity region, and an empty capacity region, wherein said full capacity region has a substantially decreasing battery voltage slope, and said intermediate capacity region has a substantially constant battery voltage slope, and said empty capacity region has a substantially increasing battery voltage slope;

a method for determining battery capacity comprising the steps of;

measuring battery voltage provided by said battery at predetermined time intervals;

determining battery voltage slopes by comparing each battery voltage with a previously measured battery voltage;

continuously comparing each battery voltage slope with a previously determined battery voltage slope;

indicating a substantially full battery capacity if said battery voltage slopes are substantially decreasing;

indicating a substantially intermediate battery capacity if said battery voltage slopes are substantially constant; and

indicating a substantially empty battery capacity if said battery voltage slopes are substantially increasing.

3. An apparatus for determining battery capacity comprising:

means for measuring battery voltages provided by said battery at predetermined time intervals;

means for determining battery voltage slopes by comparing each battery voltage with a previously measured battery voltage;

means for continuously comparing each battery voltage slope with a previously determined battery voltage slope;

means for indicating a substantially full battery capacity if said battery voltage slopes are substantially decreasing;

means for indicating a substantially intermediate battery capacity if said battery voltage slopes are substantially constant; and

means for indicating a substantially empty battery capacity if said battery voltage slopes are substantially increasing.

4. In a battery having a capacity characteristic separated into a full capacity region, an intermediate capacity region, and an empty capacity region, wherein said full capacity region has a substantially decreasing battery voltage slope, and said intermediate capacity region has a substantially constant battery voltage slope, and said empty capacity region has a substantially increasing battery voltage slope;

an apparatus for determining battery capacity comprising;

means for measuring battery voltages provided by said battery at predetermined time intervals;

means for determining battery voltage slopes by comparing each battery voltage with a previously measured battery voltage;

means for continuously comparing each battery voltage slope with a previously determined battery voltage slope;

means for indicating a substantially full battery capacity if said battery voltage slopes are substantially decreasing;

means for indicating a substantially intermediate battery capacity if said battery voltage slopes are substantially constant; and

means for indicating a substantially empty battery capacity if said battery voltage slopes are substantially increasing.