Battery control system

• US 6,600,293 B2
• Filed: 07/26/2002
• Issued: 07/29/2003
• Est. Priority Date: 08/03/2001
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kikuchi, Yoshiaki
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US10/202,836
• Publication Number:
  US 20030025479A1
• Time in Patent Office: 368 Days
• Field of Search: 320/125, 320/127, 320/128, 320/131, 320/134, 320/135, 320/136, 320/160, 320/150
• US Class Current: 320/131
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]

Abstract

A battery control system capable of relatively smoothly canceling memory effects caused to a battery mounted on a hybrid vehicle, while avoiding deterioration of the battery and vehicle performance. Upon detection of generation of charge memory effects, an HVECU changes the center of a control range for the battery'"'"'s charged amount (SOC) from its ordinary value to a value in the vicinity of an upper limit of an appropriately charged range. This SOC control is continued for a predetermined amount of time for cancellation of charge memory effects. Under such control, SOC basically varies within a range lower than where excessive charging may possibly be caused, so that battery deterioration due to excessive charging and droped power consumption due to prohibited charging can be prevented. Meanwhile, upon detection of discharge memory effects, the center of the control range is set at a value in the vicinity of a lower limit of an appropriately charged range, so that deterioration of vehicle'"'"'s dynamic performance is prevented.

Claims

1. A battery control system for controlling a charged amount of a secondary battery mounted on a hybrid vehicle such that the charged amount is maintained in the vicinity of a predetermined target charged amount level which is set within an appropriately charged range in which excessive charging and discharging are prevented, comprising:

memory effects determining means for determining generation of memory effects in the secondary battery; and

target level setting means for setting the target charged amount level at a predetermined normal level when generation of memory effects is not determined, and at a closer-to-limit level which is closer than the normal level to an upper limit or a lower limit of the appropriately charged range when generation of memory effects is determined.

2. The battery control system according to claim 1, wherein

the charged amount is controlled so as to vary within a predetermined control range which has the target charged amount level at the center and is set within the appropriate charged range, and

a control range for the closer-to-limit level is identical in size to or narrower than a control range for the normal level.

3. The battery control system according to claim 1, wherein the target level setting means maintains the target charged amount level at the closer-to-limit level for a predetermined amount of time when generation of memory effects is determined.

4. The battery control system according to claim 1, wherein the closer-to-limit level is set in the vicinity of the upper limit of the appropriately charged range.

5. A battery control system for controlling a charged amount of a secondary battery mounted on a hybrid vehicle such that the charged amount is maintained in the vicinity of a predetermined target charged amount level which is set within an appropriately charged range in which excessive charging and discharging are prevented, comprising:

memory effects determining means for determining generation of charge memory effects and discharge memory effects of the secondary battery;

target level setting means for setting the target charged amount level at a predetermined normal level when generation of charge memory effects or discharge memory effects is not determined, in the vicinity of an upper limit of the appropriately charged range when generation of charge memory effects is determined, and in the vicinity of a lower limit of the appropriately charged range when generation of discharge memory effects is determined.