POWER SUPPLY SYSTEM

• US 20100225276A1
• Filed: 09/12/2008
• Published: 09/09/2010
• Est. Priority Date: 10/03/2007
• Status: Abandoned Application

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Suzuki, Kohei, Aoki, Mamoru, Sugiyama, Shigeyuki
• Application Number:
  US12/681,272
• Publication Number:
  US 20100225276A1
• Time in Patent Office: Days
• US Class Current: 320/118
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/24 Alkaline accumulators
• CPC Class Codes: H01M 10/30 Nickel accumulators H01M10/34 takes precedence
• CPC Class Codes: H01M 10/345 Gastight metal hydride accumulators
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The power supply system of this invention includes a cell assembly in which a first assembled battery, made up of a plurality of first cells connected in series, and a second assembled battery, made up of a plurality of second cells connected in series, are connected in parallel, and a generator that charges the cell assembly. The cell assembly is configured such that an average charging voltage V1 as a terminal voltage when the first assembled battery reaches a charging capacity that is half of a full charge capacity is set to be a voltage that is smaller than an average charging voltage V2 as a terminal voltage when the second assembled battery reaches a charging capacity that is half of a full charge capacity. In addition, a resistor is connected in series to the first assembled battery.

Claims

1. A power supply system, comprising:

a cell assembly in which a first assembled battery, made up of a plurality of first cells connected in series, and a second assembled battery, made up of a plurality of second cells connected in series, are connected in parallel; and

a generator that charges the cell assembly, wherein

the cell assembly is configured such that an average charging voltage V1 as a terminal voltage when the first assembled battery reaches a charging capacity that is half of a full charge capacity is set to be a voltage that is smaller than an average charging voltage V2 as a terminal voltage when the second assembled battery reaches a charging capacity that is half of a full charge capacity, and

a resistor is connected in series to the first assembled battery.

2. The power supply system according to claim 1, wherein a resistance value of the resistor is set within a range of 30 mΩ

to 118 mΩ

for each of the plurality of first cells.

3. The power supply system according to claim 1, further comprising:

a voltage measurement unit that measures a voltage of the first assembled battery;

a switch that is connected in parallel to the resistor and that switches ON/OFF a connection between the first assembled battery and the generator; and

a control unit that switches ON/OFF of the switch based on a measurement result of the voltage measurement unit, wherein

the control unit performs control so as to turn ON the switch when determination is made that a voltage of the first assembled battery measured by the voltage measurement unit has dropped over time.

4. The power supply system according to claim 3, wherein the control unit performs control so as to turn OFF the switch when determination is made that a voltage of the first assembled battery measured by the voltage measurement unit has reached a discharge end voltage Vs.

5. The power supply system according to claim 1, further comprising a diode that is connected in parallel to the resistor, wherein

a cathode is connected to the generator.

6. The power supply system according to claim 1, wherein a ratio V2/V1 of an average charging voltage V1 of the first assembled battery to an average charging voltage V2 of the second assembled battery is set within a range of 1.01 to 1.18.

7. The power supply system according to claim 1, wherein the first cell is a nonaqueous electrolyte secondary battery.

8. The power supply system according to claim 7,

wherein lithium composite oxide containing cobalt is used as an active material of a positive electrode of the nonaqueous electrolyte secondary battery.

9. The power supply system according to claim 7, wherein the discharge end voltage Vs is set within a range of 2.2V to 3.7V for each of the plurality of first cells.

10. The power supply system according to claim 7, wherein the first assembled battery is configured by a third cell of an alkaline storage battery further connected in series to the plurality of first cells connected in series.

11. The power supply system according to claim 10, wherein a capacity of the third cell is larger than a capacity of the first cell.

12. The power supply system according to claim 1, wherein an alkaline storage battery is used as the second cell.