Battery charging method and device thereof

• US 8,076,905 B2
• Filed: 07/18/2008
• Issued: 12/13/2011
• Est. Priority Date: 10/12/2007
• Status: Active Grant

• Current Assignee: Acer, Inc.
• Original Assignee: Acer, Inc.
• Inventors: Juan, Kuan-Chi, Ko, Hui Pin
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US12/218,826
• Publication Number:
  US 20090096428A1
• Time in Patent Office: 1,243 Days
• Field of Search: 320/107, 320/116, 320/128, 320/130, 320/134, 320/136, 320/160
• US Class Current: 320/134
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery charging method and device thereof are disclosed. The method includes the following steps. First, a charging current is supplied into a plurality of cell blocks of a battery module for charging, and the terminal voltages of the cell blocks are detected, when one of said terminal voltages exceeds a first threshold, the charging is kept continuously over a first preset time period. If one of said terminal voltages of said cell blocks exceeds a second threshold, an over voltage protection is performed, else the charging current is reduced and the battery module is charged by the reduced charging current continuously over a second preset time period and if the cell blocks are determined that they are fully charged, the charging is stopped, otherwise, the battery module is charged continuously. Therefore, the battery charging method and device thereof in accordance with the present invention can prevent the battery module from being overcharged and prolong its life.

Claims

1. A battery charging method including the steps of:

(a) supplying a charging current into a battery module having a plurality of cell blocks for charging;

(b) detecting the terminal voltages of said cell blocks;

(c) continuously charging over a first preset time period if one of said terminal voltages exceeds a first threshold;

(c′

) determining whether or not one of said terminal voltages of said cell blocks exceeds a second threshold, and performing step (d) if one of said terminal voltages of said cell blocks exceeds said second threshold, otherwise performing step (e);

(d) performing an over voltage protection; and

(e) determining whether or not said cell blocks are fully charged, and stopping charging if said cell blocks are fully charged, otherwise performing step (a) or step (c′

).

2. The battery charging method of claim 1, wherein the step (e) further includes sub-steps of:

stopping charging said battery module over a second preset time period; and

determining whether or not one of said terminal voltages falls below a third threshold, wherein said cell blocks are determined being not fully charged if one of said terminal voltages falls below a third threshold, otherwise, said cell blocks are determined being fully charged.

3. The battery charging method of claim 1, wherein said first threshold is smaller than the voltage value in which said cell block is fully charged.

4. The battery charging method of claim 1, wherein the second threshold is greater than the voltage value in which said cell block is fully charged.

5. The battery charging method of claim 2, wherein the step (e) further includes including a sub-step of:

continuously charging over a third preset time period if said cell blocks are determined being not fully charged.

6. A battery charging method including the steps of:

(a) supplying a charging current into a battery module having a plurality of cell blocks for charging;

(b) detecting the terminal voltages of said cell blocks;

(c) continuously charging over a first preset time period when one of said terminal voltages exceeds a first threshold;

(c′

) determining whether or not one of said terminal voltages of said cell blocks exceeds a second threshold, and performing step (d) if one of said terminal voltages of said cell blocks exceeds a second threshold, otherwise, performing step (e);

(d) performing an over voltage protection;

(e) reducing the charging current and continuously supplying reduce charging current over a second preset time period; and

(f) determining whether or not said cell-blocks are fully charged, and stopping charging if said cell-blocks are determined being fully charged;

otherwise, performing step (a) or step (c′

).

7. The battery charging method of claim 6, wherein the step (f) further includes a sub-step of:

determining whether one of the terminal voltages falls below a third threshold, wherein said cell blocks are determined being not fully charged if one of the terminal voltages falls below a third threshold, otherwise, said cell blocks are determined being fully charged.

8. The battery charging method of claim 6, wherein the first threshold is smaller than the voltage value in which said cell blocks are fully charged.

9. The battery charging method of claim 6, wherein the second threshold is greater than the voltage value in which said cell blocks are fully charged.

10. The battery charging method of claim 7, wherein the step (f) further includes a sub-step of:

continuously charging over a third preset time period if said cell blocks are determined being not fully charged.

11. A battery charging device, applied for a battery module having a plurality of cell blocks, said battery charging device comprising:

a charging module for supplying a charging current into said cell blocks;

an over voltage protection module for providing an over voltage protection function to said cell blocks; and

a control module for detecting the terminal voltages of said cell blocks, when one of said terminal voltages exceeds a first threshold, said control module continuously supplying said charging current into said battery module over a first preset time period, and then determining whether or not one of said terminal voltages of said cell blocks exceeds a second threshold.

12. The battery charging device of claim 11, wherein said control module enables said over voltage protection module to provide said voltage protection function if the control module determines that one of said terminal voltages of said cell blocks exceeds said second threshold after said first preset time period.

13. The battery charging device of claim 11, wherein said control module controls said charging module to reduce said charging current and continuously supplying said reduced charging current over a second preset time period if said control module determines one of terminal voltages of the cell blocks falls below said second threshold after said first preset time period.

14. The battery charging device of claim 13, wherein said control module determines whether or not one of said cell blocks falls below said third threshold after said charging module charges said battery module over said second preset time period, and said control module determines that cell blocks are not fully charged if one of said cell blocks falls below said third threshold, otherwise, said control module determines that cell blocks are fully charged.

15. The battery charging device of claim 11, wherein said charging device further comprises an built-in memory for storing said first threshold, said second threshold, said third threshold, said first preset time period and said second preset time period.

16. The battery charging device of claim 11, wherein said control module comprises a counter to calculate said preset time periods.

17. The battery charging device of claim 11, wherein said first threshold is smaller than the voltage value in which said cell blocks are fully charged.

18. The battery charging device of claim 11, wherein said second threshold is greater than the voltage value in which said cell blocks are fully charged.