BATTERY STATE CONTROL CIRCUIT, BATTERY STATE CONTROL DEVICE, AND BATTERY PACK

• US 20150236533A1
• Filed: 02/13/2015
• Published: 08/20/2015
• Est. Priority Date: 02/14/2014
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Yamamoto, Norifumi, Nakamura, Akira
• Granted Patent: US 9,755,439 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 5/00 Circuit arrangements for transfer of electric power between ac networks and dc networks H02J3/36 takes precedence
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters

Abstract

A battery state control circuit is provided for connection to multiple rechargeable batteries, the multiple batteries being connected in series, for connection to a primary coil connected in series to the multiple batteries, and for connection to multiple secondary coils to which electrical energy stored in the primary coil is transferred, the multiple secondary coils being connected in parallel to the multiple batteries, respectively. The battery state control circuit includes an adjustment unit to adjust the energy amount stored in the primary coil, in accordance with a state of at least one of the multiple batteries.

Claims

1. A battery state control circuit for connection to multiple rechargeable batteries, the multiple batteries being connected in series, for connection to a primary coil connected in series to the multiple batteries, and for connection to multiple secondary coils to which electrical energy stored in the primary coil is transferred, the multiple secondary coils being connected in parallel to the multiple batteries, respectively, the battery state control circuit comprising:

an adjustment unit to adjust the energy amount stored in the primary coil, in accordance with a state of at least one of the multiple batteries.

2. The battery state control circuit as claimed in claim 1, wherein the primary coil repeats a cycle of storing and releasing the energy, and wherein the adjustment unit adjusts a length of a storing period during which the primary coil stores the energy, relative to the cycle, in accordance with the state of the batteries.

3. The battery state control circuit as claimed in claim 1, wherein the primary coil repeats a cycle of storing and releasing the energy, and wherein the adjustment unit adjusts a length of the cycle relative to a storing period during which the primary coil stores the energy, in accordance with the state of the batteries.

4. The battery state control circuit as claimed in claim 1, further comprising:

a terminal to which a charger connection signal indicating that a charger is connected for charging the multiple batteries is input;

wherein the adjustment unit adjusts the energy amount, in accordance with the charger connection signal serving to indicate the state of the batteries.

5. The battery state control circuit as claimed in claim 4, wherein the adjustment unit sets the energy amount to be greater when the charger connection signal is input to the terminal, than when the charger connection signal is not input.

6. The battery state control circuit as claimed in claim 1, further comprising:

a voltage detection circuit to detect respective voltages of the batteries;

wherein the adjustment unit adjusts the energy amount, in accordance with the detected voltages serving to indicate the state of the batteries.

7. The battery state control circuit as claimed in claim 1, further comprising:

a connection terminal connectable to a load or a charger; and

an AD converter to detect a value of a current flowing between the batteries and the connection terminal;

wherein the adjustment unit adjusts the energy amount, in accordance with the current value detected by the AD converter, the current value serving to indicate the state of the batteries.

8. The battery state control circuit as claimed in claim 7, wherein the adjustment unit increases the energy amount when an absolute value of the current value detected by the AD converter is greater than a predetermined threshold current.

9. The battery state control circuit as claimed in claim 1, further comprising:

a drive switching element connected in series to the primary coil; and

a control unit to control switching ON/OFF of the drive switching element.

10. The battery state control circuit as claimed in claim 9, wherein the primary coil repeats a cycle of storing and releasing the energy,

wherein the adjustment unit includes a current adjustment circuit having multiple resistors connectable to the primary coil via the drive switching element, and

wherein the current adjustment circuit changes connection of the multiple resistors to adjust a threshold current for switching ON/OFF of the drive switching element, for adjusting a length of a storing period during which the primary coil stores the energy, relative to the cycle.

11. The battery state control circuit as claimed in claim 9, wherein the primary coil repeats a cycle of storing and releasing the energy,

wherein the adjustment unit includes a frequency adjustment circuit having multiple resistors connectable to the control unit, and

wherein the frequency adjustment circuit changes the connection of the resistors to adjust a switching frequency to define an ON/OFF cycle of switching of the drive switching element, for adjusting a length of the cycle relative to a storing period during which the primary coil stores the energy.

12. The battery state control circuit as claimed in claim 9, wherein, the control unit keeps the drive switching element in an off state, so that the adjustment unit sets the energy amount to be zero.

13. A battery state control device comprising:

a transformer, connected to multiple rechargeable batteries, the multiple batteries being connected in series, the transformer including

a primary coil connected in series to the multiple batteries; and

multiple secondary coils to which electrical energy stored in the primary coil is transferred, the multiple secondary coils being connected in parallel to the multiple batteries, respectively, and

a battery state control circuit for connection to the multiple batteries, the primary coil, and the multiple secondary coils, the battery state control circuit including;

an adjustment unit to adjust the energy amount stored in the primary coil in accordance with a state of at least one of the multiple batteries.

14. A battery pack comprising:

a battery assembly having multiple rechargeable batteries, the multiple batteries being connected in series;

a transformer, connected to the battery assembly, the transformer including

a primary coil connected in series to the multiple batteries; and

multiple secondary coils to which electrical energy stored in the primary coil is transferred, the multiple secondary coils being connected in parallel to the multiple batteries, respectively, and

a battery state control circuit for connection to the multiple batteries, the primary coil, and the multiple secondary coils, the battery state control circuit including

an adjustment unit to adjust the energy amount stored in the primary coil, in accordance with a state of at least one of the multiple batteries.