Battery charging method

• US 6,281,663 B1
• Filed: 11/13/2000
• Issued: 08/28/2001
• Est. Priority Date: 11/11/1999
• 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: Sakurai, Takeshi, Yagi, Kazuhiko, Ishikura, Takashi
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/709,578
• Time in Patent Office: 288 Days
• Field of Search: 320/124, 320/125, 320/132, 320/137, 320/150, 320/152, 320/153
• US Class Current: 320/150
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/305 Communication interfaces
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/26 by cooling
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• 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 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

A reduction in charging time is achieved while suppressing any deterioration in the lifetime of the battery. A battery temperature increase margin is determined from the battery temperature at charge commencement and the upper limit value of the battery temperature. Moreover, the target charging capacity is determined from the initial state of charge at charge commencement and the target state of charge at charge completion. Furthermore, a value of an upper limit of the battery temperature increase is determined from these. Then, the battery charge current maximum value is set by map referral based on the value of an upper limit of the battery temperature increase such that the temperature of the battery during charging does not exceed the upper limit value. A driver performs the battery charging using a charge current value that has been set on the basis of the battery charge maximum value.

Claims

1. A method for charging a battery, comprising the steps of:

detecting a battery temperature at the start of the charging;

setting a value of an upper limit of the battery temperature during charging;

determining a maximum value for a battery charge current such that said battery temperature during charging does not exceed said value of the upper limit of the battery temperature, based on said battery temperature at the start of the charging and characteristics of battery temperature increase caused by charge current; and

charging said battery based on said maximum value for the battery charge current.

2. A method according to claim 1, wherein said maximum value for the battery charge current is determined using said battery temperature at the start of the charging, the battery state of charge at the start of the charging, said value of the upper limit of the battery temperature, and the battery state of charge at charge completion.

3. A method according to claim 1, wherein the step of determining said maximum value for the battery charge current includes the steps of:

determining an amount of current for charging the battery based on the battery state of charge at the start of the charging and the battery state of charge at charge completion;

determining a battery temperature increase margin from said battery temperature at the start of the charging and said value of the upper limit of the battery temperature;

determining a value of an upper limit of the battery temperature increase per unit of charge amount from said amount of current for charging the battery and said battery temperature increase margin; and

determining said maximum value for the battery charge current based on said value of the upper limit of the battery temperature increase per unit of charge amount and an amount of a decrease in the battery temperature caused by a battery cooling device.