Rechargeable battery with charge control

• US 20060186857A1
• Filed: 02/23/2005
• Published: 08/24/2006
• Est. Priority Date: 02/23/2005
• Status: Abandoned Application

• Current Assignee: SAFT SA (Totalenergies Se)
• Original Assignee: SAFT SA (Totalenergies Se)
• Inventors: Hoffman, Philip K., Matty, Thomas C.
• Application Number:
  US11/062,846
• Publication Number:
  US 20060186857A1
• Time in Patent Office: Days
• US Class Current: 320/122
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The battery comprises rechargeable battery cell(s), a current regulator varying a charge current provided to the battery cell(s) and a bypass circuit allowing a discharge current provided by the battery cell(s) to bypass the current regulator. The current regulator can limit the charge current depending on the amperage of the charge current and of the temperature of the current regulator. Two connecting terminals provide the charge current to the battery cell(s) and output the discharge current provided by battery cell(s). This battery can be used in existing applications to replace other type of batteries for which the current-generating equipment of the application for charging the battery was originally designed without requiring modification thereof.

Claims

1. A rechargeable battery, comprising:

at least one rechargeable battery cell;

two connecting terminals adapted to connect the battery to an external electric circuit, to provide a charge current to the at least one battery cell and to output a discharge current provided by the at least one battery cell;

a transistor adapted to provide a variable resistance;

a shunt resistor;

a transistor control circuit; and

a diode;

wherein;

the at least one battery cell, the transistor and the shunt resistor are connected in series between the two connecting terminals;

the transistor control circuit is adapted to vary the resistance provided by the transistor for limiting the charge current provided to the at least one cell depending on the amperage sensed by the shunt resistor; and

the diode is connected in parallel with both the transistor and the shunt resistor to allow the discharge current provided by the at least one battery cell to bypass the transistor and the shunt resistor.

2. The rechargeable battery according to claim 1, further comprising a temperature sensor adapted to sense a temperature of the transistor and wherein the transistor control circuit is further adapted to vary the resistance provided by the transistor depending on the temperature sensed by the temperature sensor.

3. The rechargeable battery according to claim 2, wherein the temperature sensor comprises a thermistor.

4. The rechargeable battery according to claim 2, further comprising an overcharge protection circuit adapted to cause the transistor to interrupt the charge current provided to the at least one cell when a voltage of the at least one cell is greater than a preset value.

5. The rechargeable battery according to claim 1, further comprising an overcharge protection circuit adapted to cause the transistor to interrupt the charge current provided to the at least one cell when a voltage of the at least one cell is greater than a preset value.

6. The rechargeable battery according to claim 1, further comprising:

an overcharge protection circuit; and

a switch;

wherein;

the at least one battery cell, the transistor, the switch and the shunt resistor are connected in series between the two connecting terminals;

the diode is connected in parallel with the switch, the transistor and the shunt resistor to allow a discharge current provided by the at least one battery cell to bypass the switch, the transistor and the shunt resistor for reaching the two terminals; and

the overcharge protection circuit is adapted to open the switch when a voltage of the at least one cell is greater than a preset value.

7. The rechargeable battery according to claim 1, wherein the at least one battery cell is of the lithium-ion type.

8. A rechargeable battery, comprising:

at least one rechargeable battery cell;

two connecting terminals adapted to connect the battery to an external electric circuit, to provide a charge current to the at least one battery cell and to output a discharge current provided by the at least one battery cell;

a current sensor adapted to sense an amperage of the charge current provided to the at least one cell;

a current regulator adapted to limit the charge current provided to the at least one cell depending on the amperage sensed by the current sensor; and

a bypass circuit adapted to allow the discharge current provided by the at least one battery cell to bypass the current regulator.

9. The rechargeable battery according to claim 8, wherein the current regulator comprises:

a transistor adapted to provide a variable resistance;

a transistor control circuit;

wherein;

the transistor and the at least one battery cell are connected in series between the two connecting terminals; and

the transistor control circuit is adapted to vary the resistance provided by the transistor for limiting the charge current provided to the at least one cell depending on the amperage sensed by the current sensor.

10. The rechargeable battery according to claim 8, wherein the current regulator comprises:

a transistor;

a transistor control circuit;

wherein;

the transistor and the at least one battery cell are connected in series between the two connecting terminals; and

the transistor control circuit is adapted to cause the transistor to work as a chopper having a variable duty cycle and to vary the duty cycle for limiting the charge current provided to the at least one cell depending on the amperage sensed by the current sensor.

11. The rechargeable battery according to claim 8, wherein the current sensor comprises a shunt resistor connected in series with the at least one battery cell.

12. The rechargeable battery according to claim 11, wherein the bypass circuit is further adapted to allow the discharge current provided by the at least one battery cell to bypass the shunt resistor.

13. The rechargeable battery according to claim 8, wherein the bypass circuit comprises a diode connected to allow the discharge current provided by the at least one battery cell to bypass the current regulator.

14. The rechargeable battery according to claim 8, further comprising a temperature sensor adapted to sense a temperature of the current regulator and wherein the current regulator is further adapted to limit the charge current provided to the at least one cell depending on the temperature sensed by the temperature sensor.

15. The rechargeable battery according to claim 14, wherein the temperature sensor comprises a thermistor.

16. The rechargeable battery according to claim 8, further comprising an overcharge protection circuit adapted to interrupt the charge current provided to the at least one cell when a voltage of the at least one cell is greater than a preset value.

17. A rechargeable battery, comprising:

at least one rechargeable battery cell;

a current regulator adapted to vary a charge current provided to the at least one battery cell; and

a bypass circuit adapted to allow a discharge current provided by the at least one battery cell to bypass the current regulator.

18. The rechargeable battery according to claim 17, further comprising two connecting terminals adapted:

to connect the battery to an external electric circuit;

to provide the charge current to said at least one battery cell; and

to output the discharge current provided by the at least one battery cell.

19. The rechargeable battery according to claim 17, further comprising a temperature sensor adapted to sense a temperature of the current regulator and wherein the current regulator is adapted to limit the charge current provided to the at least one cell depending on the temperature sensed by the temperature sensor.

20. The rechargeable battery according to claim 17, further comprising an overcharge protection circuit adapted to interrupt the charge current provided to the at least one cell when a voltage of the at least one cell is greater than a preset value.