Self-adjusting battery diagnostic method for continuously providing best prediction of battery reserve time

• US 6,137,292 A
• Filed: 05/03/1999
• Issued: 10/24/2000
• Est. Priority Date: 05/03/1999
• Status: Expired due to Term

• Current Assignee: ABB Power Electronics Inc. (ABB Limited)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Johnson, Mark Allen, Kakalec, Robert John, Hirsch, Marc Daniel, Ng, Patrick Kwok-Yeung
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): Toatley, Jr., Gregory J.
• Application Number:
  US09/303,875
• Time in Patent Office: 540 Days
• Field of Search: 324/427, 324/432, 320/132, 320/133, 364/483, 702/63
• US Class Current: 324/427
• CPC Class Codes: G01R 31/3647 for determining the ability of a battery to perform a critical function, e.g. cranking
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm

Abstract

A battery diagnostic method for monitoring the status of a battery in an electrical system and continuously providing a relatively accurate prediction of battery condition and performance, more particularly, a self-adjusting method for providing the best possible prediction of a battery'"'"'s reserve time before, during, and after a battery discharge. The method of the present invention utilizes different prediction methods depending on what state the electrical system is in; that is, before, during or after a battery discharge. By determining what state the system is in, the most effective prediction method can be utilized to provide an accurate battery reserve time. By providing a relatively accurate continuous reserve time prediction, the method helps prevent a complete loss of power in an electrical system relying on a battery to supply the system'"'"'s electrical power.

Claims

1. A method of monitoring the condition of a battery in an electrical system in order to provide a prediction of battery reserve time, comprising the steps of:

a) making an initial prediction of battery reserve time (t);

b) adjusting the prediction of battery reserve time for changing load conditions in the electrical system until a battery discharge is sensed;

c) adjusting the prediction of battery reserve time by summing capacity discharged from battery (AH_out) and capacity restored to battery (AH_in) until the end of Coup de Fouet portion of battery discharge is sensed;

d) calculating battery reserve time using diagnostic discharge method until end of battery discharge and beginning of battery recharge is sensed;

e) adjusting battery reserve time by summing capacity discharged from battery (AH_out) and capacity restored to battery (AH_in) until end of battery recharge is sensed; and

f) repeating step b) through step f).