Method of charging a storage battery

• US 6,781,348 B2
• Filed: 03/26/2003
• Issued: 08/24/2004
• Est. Priority Date: 03/27/2002
• Status: Expired due to Fees

• Current Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Original Assignee: Fuji Jukogyo KK (Subaru Corp.)
• Inventors: Yokohama, Yutaka
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US10/396,828
• Publication Number:
  US 20030184261A1
• Time in Patent Office: 517 Days
• Field of Search: 320/124, 320/125, 320/131, 320/132, 320/160, 320/DIG.17, 320/DIG.21
• US Class Current: 320/125
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/007184 in response to battery voltage gradient
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

A method of charging a storage battery comprising executing an n(n≧2)-stage constant current charging process charging the battery with a constant current while monitoring a terminal voltage of the battery, the current decreasing stepwise n−1 times every time the terminal voltage coincides with a current switching voltage. The method further comprises measuring a depth of discharge of the battery immediately before charging and executing an additional charging process before the n-stage constant current charging process when the depth of discharge is deeper than a reference depth of discharge, the additional charging process charging the battery with an additional constant current larger than an initial current in the n-stage constant current charging process and switching the additional current to the initial current when the terminal voltage coincides with the current switching voltage, so as to attain a rapid charging of the battery at a low cost.

Claims

1. A method of charging a storage battery comprising executing an n(n≧

2)-stage constant current charging process charging the battery with a constant current while monitoring a terminal voltage of the battery, the current decreasing stepwise n−

1 times every time the terminal voltage coincides with a current switching voltage, wherein, the method further comprises;

measuring a depth of discharge of the battery immediately before charging; and

executing an additional charging process before the n-stage constant current charging process when the depth of discharge is deeper than a reference depth of discharge, the additional charging process charging the battery with an additional constant current larger than an initial current in the n-stage constant current charging process and switching the additional current to the initial current when the terminal voltage coincides with the current switching voltage.

2. The method of charging the storage battery as claimed in claim 1, wherein, the storage battery is a lead storage battery.

3. The method of charging the storage battery as claimed in claim 1, wherein, the additional current in the additional charging process is set so that the additional current increases stepwise as the depth of discharge of the battery increases.

4. The method of charging the storage battery as claimed in claim 1, wherein, the additional current in the additional charging process is set so that the additional current increases continuously as the depth of discharge of the battery increases.

5. The method of charging the storage battery as claimed in claim 1, wherein, the method further comprises selecting one of a normal charging mode and an additional charging mode, and the additional charging process is executed only when the additional charging mode is selected.

6. The method of charging the storage battery as claimed in claim 1, wherein, the method further comprises detecting a starting time of charging, and the additional charging process is executed only when the starting time of charging is within a time predetermined for each of the battery so as to level off commercial electric power consumption per hour.

7. The method of charging the storage battery as claimed in claim 1, wherein, the method further comprises detecting a starting time of charging and the additional charging process is executed only when the starting time of charging is within a time during which a discount commercial electric power rate is applied.

8. The method of charging the storage battery as claimed in claim 1, wherein, the method further comprises detecting a temperature of the storage battery immediately before charging, and the additional charging process is executed only when the temperature of the battery is lower than a temperature at which a reduction in the life of the battery begins to accelerate.

9. The method of charging the storage battery as claimed in claim 6, wherein, the method further comprises detecting a temperature of the storage battery immediately before charging, and the additional charging process is executed only when the temperature of the battery is lower than a temperature at which a reduction in the life of the battery begins to accelerate.

10. The method of charging the storage battery as claimed in claim 7, wherein, the method further comprises detecting a temperature of the storage battery immediately before charging, and the additional charging process is executed only when the temperature of the battery is lower than a temperature at which a reduction in the life of the battery begins to accelerate.

11. The method of charging the storage battery as claimed in claim 8, wherein, the additional current of the additional charging process is set so that the additional current decreases stepwise as the temperature of the battery increases.

12. The method of charging the storage battery as claimed in claim 8, wherein, the additional current of the additional charging process is set so that the additional current decreases continuously as the temperature of the battery increases.