Battery control apparatus for hybrid vehicle

• US 6,232,748 B1
• Filed: 08/24/2000
• Issued: 05/15/2001
• Est. Priority Date: 08/27/1999
• 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: Kinoshita, Naoki
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/644,768
• Time in Patent Office: 264 Days
• Field of Search: 320/104, 320/123, 320/132, 320/150, 320/153, 324/426, 324/427, 324/431, 324/433
• US Class Current: 320/132
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60K 6/54 Transmission for changing ratio
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/1415 with a generator driven by a prime mover other than the motor of a vehicle
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/917 with transmission for changing gear ratio

Abstract

The present invention relates a battery control apparatus (9) controls charge/discharge processes of a battery (8) installed in a hybrid vehicle, according to the battery temperature so as to prevent degradation of the battery performance. The vehicle has a combustion engine (1) for providing a driving force, an electric motor (2) for generating a drive assist force for assisting the output of the engine, wherein the battery supplies electrical power to the motor, and, when the drive-assist force is not required by the engine, the motor is used as a generator to charged the battery, the apparatus is comprised by: a residual battery charge computation device (91) for computing a level of residual battery charge in the battery; a battery temperature measuring device for measuring a temperature of the battery; and a charge/discharge controller (92) that operates in such a way that, when a battery temperature measured by the battery temperature measuring device exceeds a threshold temperature, the charge/discharge controller permits only discharging until the residual battery charge is lowered to a level defined by a first specified value.

Claims

1. An apparatus for controlling a battery installed in a hybrid vehicle having a combustion engine for providing a driving force, an electric motor for generating a drive-assist force for assisting the output of the engine, wherein said battery supplies electrical power to the motor, and, when the drive-assist force is not required by the engine, said motor is used as a generator to charged the battery, said apparatus is comprised by:

a residual battery charge computation device for computing a level of residual battery charge in the battery;

a battery temperature measuring device for measuring a temperature of the battery; and

a charge/discharge controller that operates in such a way that, when a battery temperature measured by the battery temperature measuring device exceeds a threshold temperature, said charge/discharge controller permits only discharging until the residual battery charge is lowered to a level defined by a first specified value.

2. An apparatus according to claim 1, wherein, after said battery reaches said first specified value of residual battery charge, said charge/discharge controller permits the battery to be charged a level not exceeding a level defined by a second specified value of the residual battery charge, which is higher than said first specified value of the residual battery charge.

3. An apparatus according to one of claim 1 or 2, wherein the residual battery charge computation device determines whether a battery voltage is at a low-limit of the battery voltage, and defines a detected low-limit of battery voltage as representing the use-permitted low-limit of the residual battery charge.