Parallel hybrid battery pack charging

• US 7,518,338 B2
• Filed: 04/13/2006
• Issued: 04/14/2009
• Est. Priority Date: 04/13/2006
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Sterz, Stephen D., Wang, Ligong
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US11/403,264
• Publication Number:
  US 20070247107A1
• Time in Patent Office: 1,097 Days
• Field of Search: 320/107, 320/116, 320/117, 320/126, 320/127, 320/128, 320/134, 320/160, 320/125
• US Class Current: 320/125
• CPC Class Codes: H02J 7/0071 with a programmable schedule

Abstract

For charging a rechargeable hybrid battery pack, a first cell stack coupled in parallel with a second cell stack of the hybrid battery pack are pre-charged in parallel. The cell stack to first complete the pre-charge phase, is selected to receive a normal charge with a constant current while the non-selected one of the cell stack continues to receive the pre-charge. The first cell stack and the second cell stack receive the normal charge in the selected sequence. Upon completion of the normal charge for each cell of the hybrid battery pack, the first cell stack and the second cell stack are trickle-charged in parallel to complete the charging.

Claims

1. A charge circuit for a hybrid battery pack, the charge circuit comprising:

a first switch operable to provide a charge to a first cell stack of the hybrid battery pack;

a first charge switch coupled in parallel with the first switch;

a second switch operable to provide the charge to a second cell stack of the hybrid battery pack, wherein the first cell stack and the second cell stack are coupled in parallel;

a second charge switch coupled in parallel with the second switch; and

a controller to control each one of the first switch and the second switch in accordance with a parallel charging sequence for the first cell stack and the second cell stack, wherein the parallel charging sequence includes providing the charge to the first cell and to the second cell in parallel during a pre-charge phase and during a trickle-charge phase.

2. The charge circuit of claim 1, wherein the charge received in parallel by the first cell stack and the second cell stack during the pre-charge phase increases a voltage of each one of the first cell stack and the second cell stack above a threshold voltage.

3. The charge circuit of claim 2, wherein the charge received in parallel by the first cell stack and the second cell stack during the trickle-charge phase increases the voltage above the threshold voltage to a fully charged voltage.

4. The charge circuit of claim 1, comprising:

the controller operable to control the first charge switch the second charge switch, wherein the first charge switch and the second charge switch are operable to provide the charge to the first cell stack and the second cell stack respectively in accordance with a serial charging sequence during a normal charge phase, wherein the charge provided during the serial charging sequence is greater compared to the parallel charging sequence.

5. The charge circuit of claim 4, wherein operation of the first switch and the first charge switch is complementary, wherein operation of the second switch and the second charge switch is complementary.

6. The charge circuit of claim 1, wherein the first switch includes a variable first resistor coupled in series, wherein the variable first resistor controls an amount of the charge flowing through the first switch.

7. The charge circuit of claim 1, wherein the second switch includes a variable second resistor coupled in series, wherein the variable second resistor controls an amount of the charge flowing through the second switch.

8. A method for charging a rechargeable hybrid battery pack, the method comprising:

pre-charging a first cell stack and a second cell stack, wherein the pre-charging of the first cell stack and the second cell stack occurs in parallel, wherein the hybrid battery pack includes the first cell stack and the second cell stack;

charging the first cell stack and the second cell stack, wherein the charging occurs with a constant current charge provided in sequence to one of the first cell stack and the second cell stack; and

trickle-charging the first cell stack and the second cell stack, wherein the trickle-charging of the first cell stack and the second cell stack occurs in parallel.

9. The method of claim 8, wherein the first cell stack includes a first cell type and the second cell stack includes a second cell type, wherein the first cell type and the second cell type are different.

10. The method of claim 9, wherein the first cell type is of a prism shape and the second cell type is of a cylindrical shape.

11. The method of claim 8, wherein one of the first cell stack and the second cell stack is pre-charging while another one of the first cell stack and the second cell stack is charging with the constant current charge.

12. The method of claim 8, wherein the charging occurs in response to a completion of the pre-charging, wherein the trickle-charging occurs in response to a completion of the charging.

13. The method of claim 8, wherein an amount of the constant current charge provided to the first cell stack and the second cell stack is substantially greater in comparison to a charge provided during the pre-charging phase and the trickle-charging phase.

14. The method of claim 8, wherein the sequence includes providing the constant current charge to a first one of the first cell stack and the second cell stack that has completed the pre-charging.

15. An information handling system (IHS) comprising:

a processor;

a hybrid rechargeable battery operable to provide power to the processor, wherein the hybrid rechargeable battery includes;

a first cell stack operable to store the power; and

a second cell stack coupled in parallel to the first cell stack, wherein the second stack is operable to store the power;

a first switch operable to provide a charge to the first cell stack;

a first charge switch coupled in parallel with the first switch;

a second switch operable to provide the charge to the second cell stack;

a second charge switch coupled in parallel with the second switch; and

a controller to control each one of the first switch and the second switch in accordance with a parallel charging sequence for the first cell stack and the second cell stack, wherein the parallel charging sequence includes providing the charge to the first cell and to the second cell in parallel during a pre-charge phase and during a trickle-charge phase.

16. The system of claim 15, comprising:

the controller operable to control the first charge switch and the second charge switch, wherein the first charge switch and the second charge switch are operable to provide the charge to the first cell stack and the second cell stack respectively in accordance with a serial charging sequence during a normal charge phase, wherein the charge provided during the serial charging sequence is greater compared to the parallel charging sequence.

17. The system of claim 16, wherein operation of the first switch and the first charge switch is complementary, wherein operation of the second switch and the second charge switch is complementary.

18. The system of claim 15, wherein each one of the first switch and the second switch includes a variable resistor coupled in series, wherein the variable resistor controls an amount of the charge correspondingly flowing through the first switch and the second switch.