Battery system with levelled discharge

• US 5,663,628 A
• Filed: 07/20/1995
• Issued: 09/02/1997
• Est. Priority Date: 09/08/1994
• Status: Expired due to Term

• Current Assignee: Solar World International Co., Ltd.
• Original Assignee: Ueda Co., Ltd.
• Inventors: Fujii, Takashi
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US08/504,313
• Time in Patent Office: 775 Days
• Field of Search: 320/1, 320/3, 320/5, 320/8, 320/9, 320/13, 320/14, 320/25, 320/40, 320/51, 320/54, 320/55, 320/61, 136/291, 136/293
• US Class Current: 362/183
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10S 362/802 Position or condition responsive switch

Abstract

A battery system for supplying electric energy from a primary battery or a secondary battery to a load. This system includes a battery consisting of the primary battery or the secondary battery, an electric double layer capacitor for storing electric energy from the battery, a limiting resistor for limiting the electric energy supplied from the battery to the electric double layer capacitor, and a discharge controller for controlling the electric double layer capacitor. The discharge controller causes the electric double layer capacitor to discharge the electric energy to the load intermittently in predetermined cycles while charging the electric double layer capacitor. A discharging time for discharging the electric energy from the electric double layer capacitor to the load is shorter than a charging time for charging the electric double layer capacitor with electric energy. At this time, a discharge current is greater than a charge current.

Claims

1. A battery system for supplying electric energy from a primary battery or a secondary battery to a load, comprising:

a battery consisting of said primary battery or said secondary battery;

an electric double layer capacitor for storing electric energy from said battery;

a limiting resistor for limiting the electric energy supplied from said battery to said electric double layer capacitor; and

discharge control means for causing said electric double layer capacitor to discharge the electric energy to said load intermittently in predetermined cycles while charging said electric double layer capacitor, such that a discharging time for discharging the electric energy from said electric double layer capacitor to said load is shorter than a charging time for charging said electric double layer capacitor with electric energy and that a discharge current is greater than a charge current.

2. A battery system as defined in claim 1, wherein said discharge control means provides controls such that, where said discharging time is T₁, said charging time is T₂, and a sum thereof is a driving cycle T (=T₁ +T₂) of said load, said discharging time T is 1% of said driving cycle T of said load (duty ratio K=0.01).

3. A battery system as defined in claim 1, wherein said battery comprises a secondary battery chargeable by a solar battery for converting light energy into electric energy.

4. A battery system as defined in claim 3, further comprising a reverse current preventive diode connected in series between said solar battery and said secondary battery.

5. A battery system as defined in claim 4, wherein said reverse current preventive diode comprises a schottky diode.

6. A battery system as defined in claim 3, wherein said discharge control means provides controls such that, where said discharging time is T₁, said charging time is T₂, and a sum thereof is a driving cycle T (=T₁ +T₂) of said load, said discharging time T is 5% of said driving cycle T of said load (duty ratio K=0.05).

7. An intermittent motion apparatus for supplying electric energy from a primary battery or a secondary battery to a load to drive said load intermittently, said apparatus comprising:

a battery consisting of said primary battery or said secondary battery;

light emitting means such as a light emitting diode acting as said load;

an electric double layer capacitor for storing electric energy from said battery;

a limiting resistor for limiting the electric energy supplied from said battery to said electric double layer capacitor; and

discharge control means for causing said electric double layer capacitor to discharge the electric energy to said light emitting means to drive said light emitting means intermittently in predetermined cycles while charging said electric double layer capacitor, such that a discharging time for discharging the electric energy from said electric double layer capacitor to said light emitting means is shorter than a charging time for charging said electric double layer capacitor with electric energy and that a discharge current is greater than a charge current.

8. An apparatus as defined in claim 7, wherein said apparatus is a signal/guide light including a tubular indicator having a plurality of light emitting diodes arranged peripherally thereof to act as said light emitting means, a grip disposed below said indicator and having said electric double layer capacitor, said limiting resistance and said discharge control means mounted therein, a switch disposed peripherally thereof for supplying and stopping the electric energy from said electric double layer capacitor to said discharge control means, and said battery mounted in a space closable by a watertight cap attached to a bottom thereof, and a protective cover for surrounding said indicator.

9. An apparatus as defined in claim 7, wherein said discharge control means provides controls such that, where said discharging time is T₁, said charging time is T₂, and a sum thereof is a driving cycle T (=T₁ +T₂) of said light emitting means, said discharging time T is 20% of said driving cycle T (duty ratio K=0.2).

10. An apparatus as defined in claim 7, further comprising vibration detecting means for detecting vibration, and light detecting means for detecting ambient illuminance below a predetermined illuminance level, wherein said discharge control means is operable, only when said vibration detecting means and said light detecting means are both in operation, for causing said electric double layer capacitor to discharge the electric energy to said light emitting means to drive said light emitting means intermittently in predetermined cycles while charging said electric double layer capacitor, such that the discharging time for discharging the electric energy from said electric double layer capacitor to said light emitting means is shorter than the charging time for charging said electric double layer capacitor and that the discharge current is greater than the charge current.

11. An apparatus as defined in claim 7, wherein said apparatus is a bicycle safety light including a main body having a light emitting diode mounted in a front position thereof to act as said light emitting means, and a photoconductive cell disposed on an upper surface thereof to act as said light detecting means, said main body containing said electric double layer capacitor, said limiting resistor, said vibration detecting means and said discharge control means, and a light diffuser lens for forwardly and laterally diffusing light radiating from said light emitting diode.

12. An apparatus as defined in claim 11, wherein said photoconductive cell comprises a CdS (cadmium sulphide) cell.

13. An apparatus as defined in claim 11, further comprising an electrolytic capacitor connected to said electric double layer capacitor through said vibration detecting means, wherein said discharge control means is operable, when said vibration detecting means is inoperative and said light detecting means is operative, for causing said electric double layer capacitor to supply electric energy to said light emitting diode intermittently in predetermined cycles for a period according to a capacitance of said electrolytic capacitor.

14. An apparatus as defined in claim 11, wherein said light diffuser lens is centrally recessed at one end thereof to define two slant surfaces extending toward a bottom, said light emitting diode being embedded in the other end of said light diffuser lens to be opposed to said bottom.

15. An apparatus as defined in claim 10, wherein said discharge control means provides controls such that, where said discharging time is T₁, said charging time is T₂, and a sum thereof is a driving cycle T (=T₁ +T₂) of said light emitting means, said discharging time T is 5% of said driving cycle T of said light emitting means (duty ratio K=0.05).

16. An apparatus as defined in claim 7, further comprising seawater detecting means for detecting presence/absence of seawater, wherein said discharge control means is operable, only when said seawater detecting means detects seawater, for causing said electric double layer capacitor to discharge the electric energy to said light emitting means to drive said light emitting means intermittently in predetermined cycles while charging said electric double layer capacitor, such that the discharging time for discharging the electric energy from said electric double layer capacitor to said light emitting means is shorter than the charging time for charging said electric double layer capacitor and that the discharge current is greater than the charge current.

17. An apparatus as defined in claim 16, wherein said discharge control means provides controls such that, where said discharging time is T₁, said charging time is T₂, and a sum thereof is a driving cycle T (=T₁ +T₂) of said light emitting means, said discharging time T is 5% of said driving cycle T of said light emitting means (duty ratio K=0.05).

18. An apparatus as defined in claim 16, wherein said seawater detecting means includes two electrodes each approximately 5 mm square in size and arranged at an interval of about 5 mm.

19. An apparatus as defined in claim 16, wherein said electrodes are given anticorrosion treatment.

20. An apparatus as defined in claim 16, wherein said apparatus is an underwater fishing light including an upper portion and a lower portion having said electric double layer capacitor, said limiting resistor, said seawater detecting means and said discharge control means mounted therein, and a fishing line connector formed at an upper end thereof, and a lower portion connected to said upper portion and having a light emitting diode mounted therein to act as said light emitting means, a plurality of fish hooks arranged peripherally thereof, and a fishing line connector formed at a lower end thereof.