BATTERY MANAGEMENT SYSTEM AND METHOD OF DRIVING THE SAME

• US 20140139176A1
• Filed: 03/15/2013
• Published: 05/22/2014
• Est. Priority Date: 11/22/2012
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: JI, Se-Jin
• Granted Patent: US 9,787,125 B2
• Time in Patent Office: Days
• US Class Current: 320/107
• 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: Y02E 60/10 Energy storage using batteries

Abstract

A battery management system and a method of driving the same are provided. When the output signal of a charger is higher than a first voltage, a battery cell is charged with a first current by a first charge circuit. When the output signal of the charger is higher than a second voltage, a battery cell is charged with a second current by a second charge circuit. The second voltage is higher than the first voltage and second current is higher than the first current.

Claims

1. A battery management system, comprising:

a first charge circuit connected between a first terminal of a charger and a first terminal of a battery cell, wherein the first charge circuit controls charging the battery cell with a first current;

a first switch having a first terminal connected to a second terminal of the battery cell, wherein the first switch switches charging of the battery cell by control of the first charge circuit;

a second switch between a second terminal of the first switch and a second terminal of the charger, wherein the second switch switches charging of the battery cell to correspond to a value of an output signal of the charger;

a second charge circuit connected between the first terminal of the charger and the first terminal of the battery cell, wherein the second charge circuit controls charging the battery cell with a second current, the second current being higher than the first current;

a third switch having a first terminal connected to the second terminal of the battery cell, wherein the third switch switches charging of the battery cell by control of the second charge circuit; and

a fourth switch between a second terminal of the third switch and the second terminal of the charger, wherein the fourth switch switches charging of the battery cell to correspond to a value of the output signal of the charger.

2. The battery management system as claimed in claim 1, wherein:

the second switch is turned on when a value of the output signal of the charger is a first voltage, and

the fourth switch is turned on when a value of the output signal of the charger is a second voltage higher than the first voltage.

3. The battery management system as claimed in claim 2, further comprising:

a first comparator that outputs a signal that turns on the second switch to the second switch when a value of the output signal of the charger is higher than the first voltage; and

a second comparator that outputs a signal that turns on the fourth switch when a value of the output signal of the charger is the second voltage.

4. The battery management system as claimed in claim 2, further comprising:

a first comparator that outputs a signal to turn on the fourth switch when a value of the output signal of the charger is higher than the first voltage; and

an inverter that inverts the output signal of the comparator and outputs a signal to the second switch.

5. The battery management system as claimed in claim 1, wherein a turn-on resistance of the third switch is lower than a turn-on resistance of the first switch.

6. The battery management system as claimed in claim 1, wherein:

the first charge circuit turns off the first switch when a charge current that is charged at the battery cell is higher than a first reference current,

the second charge circuit turns off the third switch when a charge current that is charged at the battery cell is higher than a second reference current, and

the second reference current is higher than the first reference current.

7. The battery management system as claimed in claim 5, wherein:

the first charge circuit measures the first current through a voltage between the first terminal and the second terminal of the first switch and through the turn-on resistance of the first switch, and

the second charge circuit measures the second current through a voltage between the first terminal and the second terminal of the third switch and through the turn-on resistance of the third switch.

8. A method of driving a battery management system that controls a charge operation from a charger to a battery cell, the method comprising:

measuring an output signal of the charger;

charging, when the output signal of the charger is higher than a first voltage, the battery cell with a first current; and

charging, when the output signal of the charger is higher than a second voltage higher than the first voltage, the battery cell with a second current, the second current being higher than the first current.

9. The method as claimed in claim 8, wherein charging the battery cell with the first current includes, when the output signal of the charger is higher than the first voltage, turning on a first switch and a second switch, the first switch having a first terminal connected to the battery cell, and the second switch being between a second terminal of the first switch and the charger.

10. The method as claimed in claim 9, wherein charging the battery cell with the second current includes, when the output signal of the charger is higher than the second voltage, turning on a third switch and a fourth switch, the third switch having a first terminal connected to the battery cell, and the fourth switch being connected between a second terminal of the third switch and the charger.

11. The method as claimed in claim 10, wherein a turn-on resistance of the third switch is lower than that of the first switch.

12. The method as claimed in claim 8, wherein measuring the output signal of the charger includes:

comparing the output signal of the charger and the first voltage; and

comparing the output signal of the charger and the second voltage.

13. The method as claimed in claim 8, further comprising:

measuring a value of the first current and, if the first current is higher than a first reference current, stopping charging; and

measuring a value of the second current and, if the second current is higher than a second reference current, stopping charging.

14. The method as claimed in claim 13, wherein the second reference current is higher than the first reference current.