Battery management system and battery management method

• US 8,810,201 B2
• Filed: 11/27/2009
• Issued: 08/19/2014
• Est. Priority Date: 12/01/2008
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Yun, Han-Seok, Murakami, Yusai
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): OMAR, AHMED H
• Application Number:
  US12/626,704
• Publication Number:
  US 20100134070A1
• Time in Patent Office: 1,726 Days
• Field of Search: 320/116, 320/118
• US Class Current: 320/118
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: B60L 58/19 Switching between serial connection and parallel connection of battery modules
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: B60L 58/26 by cooling
• CPC Class Codes: B60L 58/33 by cooling
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A battery management system and a driving method thereof, to set a discharge completion voltage using the cell voltages of cells of a battery, and to balance the cell voltages according to the set discharge completion voltage.

Claims

1. A battery management system, comprising:

cells having cell voltages;

a cell balancing unit that performs a control operation to balance the cell voltages; and

a micro-control unit (MCU) that measures the cell voltages, to detect whether one or more of the cells are unbalanced, and controls the cell balancing unit to perform the control operation until the cell voltages of the one or more unbalanced cells reach a discharge completion voltage,

wherein the discharge completion voltage is equal to a difference between a highest cell voltage and a lowest cell voltage, or is equal to an average of the cell voltages of less than all of the cells.

6. The battery management system of claim 1, wherein a period for the control operation to balance the cell voltages is determined solely based on whether or not the cell voltages of the one or more unbalanced cells reach the discharge completion voltage.

2. A battery management system, comprising:

cells having cell voltages;

a cell balancing unit that performs a control operation to balance the cell voltages; and

a micro-control unit (MCU) that measures the cell voltages, to detect whether one or more of the cells are unbalanced, and controls the cell balancing unit, to perform the control operation until the cell voltages of the one or more unbalanced cells reach an average of less than all of the cell voltages or reach a voltage equal to a difference between a highest cell voltage and a lowest cell voltage.

3. The battery management system of claim 2, wherein the cell balancing unit discharges the one or more unbalanced cells until the cell voltages of the one or more unbalanced cells reach an average of highest and lowest cell voltages.

7. The battery management system of claim 2, wherein a period for the control operation to balance the cell voltages is determined solely based on whether or not the cell voltages of the one or more unbalanced cells reach the average of the at least two of the cell voltages.

4. A battery management method comprising:

measuring voltages of cells;

comparing the measured voltages of the cells to a discharge completion voltage, to determine whether one or more of the cells are unbalanced; and

discharging the one or more unbalanced cells to the discharge completion voltage,

wherein the discharge completion voltage is equal to an average of cell voltages of less than all of the cells, or is equal to a difference between a highest cell voltage and a lowest cell voltage.

8. The battery management method of claim 4, wherein a period for said discharging the one or more unbalanced cells to the discharge completion voltage is determined solely based on whether or not the voltages of the one or more unbalanced cells reach the discharge completion voltage.

5. A battery management method comprising:

measuring cell voltages of cells;

comparing the measured cell voltages to a discharge completion voltage, to determine whether one or more of the cells are unbalanced; and

discharging the one or more unbalanced cells to the discharge completion voltage,

wherein the discharge completion voltage is an average of less than all of the cell voltages, or is a difference between a highest cell voltage and a lowest cell voltage.

9. The battery management method of claim 5, wherein a period for said discharging the one or more unbalanced cells to the discharge completion voltage is determined solely based on whether or not the cell voltages of the one or more unbalanced cells reach the discharge completion voltage.