System for controlling charging of secondary battery

• US 7,391,183 B2
• Filed: 01/15/2003
• Issued: 06/24/2008
• Est. Priority Date: 01/17/2002
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Ariga, Kyoichi, Sone, Takashi
• Primary Examiner(s): Easthom; Karl
• Assistant Examiner(s): Berhanu; Samuel
• Application Number:
  US10/342,211
• Publication Number:
  US 20040232890A1
• Time in Patent Office: 1,987 Days
• Field of Search: 320/125, 320/160, 320/124, 320/131, 320/157, 320/162, 320/163, 320/164, 320/128, 320/132, 320/134, 320/136, 320/137, 320/144, 320/148, 320/149, 320/151, 320/152, 320/153, 320/156, 320/2, 320/11, 320/14, 320/19, 320/20, 320/21, 320/22, 320/23, 320/30, 320/37, 320/39, 320/43
• US Class Current: 320/125
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/007194 of the battery

Abstract

To provide a system for controlling the charging of a secondary battery (battery), which is capable of keeping an initial charging/discharging characteristic of the battery in consideration of a change in environmental temperature and deterioration of the battery with elapsed time. An ordinary charging portion for performing a first charging control specified to stop the charging at a charge level less than a full-charge level is used in combination with a refresh charging portion for performing a second charging control specified to stop the charging at a charge level more than the full charge level. After the charging by the ordinary charging portion is continuously repeated by a specific number of times, for example, ten times, the next charging is performed by the refresh charging portion. The cut-off voltage used for the ordinary charging portion and refresh charging portion is determined by correcting a reference voltage VO on the basis of an environmental temperature TAO detected by an environmental temperature detecting portion. The deterioration of the battery is corrected on the basis of a reference full-charge voltage, an initial full-charge voltage Vmax(1), a present full-charge voltage Vmax(n), an initial maximum battery temperature Tmax(1), and a present maximum battery temperature Tmax(n).

Claims

1. A system for controlling charging of a secondary battery, comprising:

first charging control means for stopping the charging when a charging voltage reaches a specific first cut-off voltage corresponding to a charge capacity less than a full-charge level; and

temperature correcting means for correcting said first cut-off voltage on the basis of a deviation between a present environmental temperature and a reference environmental temperature,

wherein the system charges the secondary battery under control of the first charging control means for number of times that is determined by a randomly selected number, and then the system charges the secondary battery under control of second charging control means.

2. The system for controlling the charging of a secondary battery according to claim 1, and further comprising:

second charging control means for stopping the charging when the charging voltage reaches a second cut-off level exceeding the full-charge level;

charging voltage storing means for storing a value of the charging voltage after charging the secondary battery a plurality of times by said second charging control means; and

deterioration correcting means for correcting said second cut-off voltage on the basis of the value of the charging voltage stored in said charging voltage storing means.

3. The system for controlling the charging of a secondary battery according to claim 2, and further comprising:

battery temperature storing means for storing a temperature value of said secondary battery after the secondary battery has been charged the plurality of times by said second charging control means;

wherein said deterioration correcting means further corrects said cut-off voltage on the basis of the temperature value of the secondary battery stored in said battery temperature storing means.

4. The system for controlling the charging of a secondary battery according to claim 1, wherein the first charging control means stops the charging of the secondary battery at a charge capacity corresponding to 97%.

5. The system for controlling the charging of a secondary battery according to claim 2, wherein the second charging control means stops the charging of the secondary battery when the charge capacity corresponds to more than 100% by a predetermined amount.

6. The system for controlling the charging of a secondary battery according to claim 3, and further comprising:

environmental temperature detecting means for detecting an environmental temperature; and

comparing means for comparing the environmental temperature to the temperature of the secondary battery,

wherein if the secondary battery temperature is equal to or less than the environmental temperature, the system determines a number of times that charging is repetitively performed under control of said first charging control means, in order to determine the charging voltage to be administered to the secondary battery.

13. The system for controlling the charging of a secondary battery according to claim 1, further comprising second charging control means for charging the secondary battery in two stages, the first stage being performed using a higher current than the second stage.

14. The system for controlling the charging of a secondary battery according to claim 13, wherein a time period for the second stage of charging the secondary battery is less than a time period for the first stage of charging the secondary battery.

7. A method for controlling the charging of a secondary battery, comprising the following steps:

stopping the charging by a first charging control means when a charging voltage reaches a specific first cut-off voltage corresponding to a charge capacity less than a full-charge level; and

correcting said first cut-off voltage on the basis of a deviation between a present environmental temperature and a reference environmental temperature;

wherein the system charges the secondary battery under control of the first charging control means for number of times that is determined by a randomly selected number, and then the system charges the secondary battery under control of second charging control means.

8. The method for controlling the charging of a secondary battery according to claim 7, and further comprising the steps of:

stopping the charging by means of a second charging control means when the charging voltage reaches a second cut-off level exceeding the full-charge level;

storing a value of the charging voltage after charging the secondary battery a plurality of times under control of the charging second charging control means; and

correcting said second cut-off voltage on the basis of the value of the stored charging voltage.

9. The method for controlling the charging of a secondary battery according to claim 8, and further comprising the steps of:

storing a temperature value of said secondary battery after the secondary battery has been charged the plurality of times by said second charging control member;

wherein said deterioration correcting step further corrects said cut-off voltage on the basis of the stored temperature value of the secondary battery.

10. The method for controlling the charging of a secondary battery according to claim 7, wherein the first charging control means stops the charging of the secondary battery at a charge capacity corresponding to 97%.

11. The method for controlling the charging of a secondary battery according to claim 8, wherein the second charging control means stops the charging of the secondary battery when the charge capacity corresponds to more than 100% by a predetermined amount.

12. The method for controlling the charging of a secondary battery according to claim 9, and further comprising the steps of:

detecting an environmental temperature; and

comparing the environmental temperature to the temperature of the secondary battery,

wherein if the secondary battery temperature is equal to or less than the environmental temperature, the system determines a number of times that charging is repetitively performed under control of said first charging control means, in order to determine the charging voltage to be administered to the secondary battery.

15. The method for controlling the charging of a secondary battery according to claim 7, further comprising second charging control means for charging the secondary battery in two stages, the first stage being performed using a higher current than the second stage.

16. The method for controlling the charging of a secondary battery according to claim 15, wherein a time period for the second stage of charging of the secondary battery is less than a time period for the first stage of charging the secondary battery.