Information handling system including a power management apparatus capable of independently switching between a primary and secondary battery

• US 6,892,147 B2
• Filed: 04/18/2003
• Issued: 05/10/2005
• Est. Priority Date: 04/18/2003
• Status: Expired due to Term

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Bui, Vinh X., Vyssotski, Nikolai V.
• Primary Examiner(s): Bui, Bryan
• Application Number:
  US10/418,794
• Publication Number:
  US 20040210406A1
• Time in Patent Office: 753 Days
• Field of Search: 702 57- 59, 702/65, 702/60, 702/62, 702/63, 702/64, 320/107, 320/118, 320/136, 320/137, 320/149
• US Class Current: 702/63
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence

Abstract

An information handling system includes a power management apparatus which is capable of selectively coupling to primary and secondary batteries that provide portable and backup power to the information handling system. The power management apparatus senses when the voltage at the power input of the information handling system drops below a predetermined threshold voltage. Respective switching diodes between the primary battery and the power input and the secondary battery and the power input are used as a means of fast hardware connection of the selected battery to the power input. Respective bypass switches are connected in parallel with the switching diodes. Control software instructs the bypass switch across the diode associated with the selected battery to close to prevent diode power loss. In this manner, a selected primary or secondary battery is independently switched to the power input, provided the selected battery exhibits a voltage greater than the predetermined threshold voltage.

Claims

1. An information handling system (IHS) coupled to a docking station comprising:

a processor coupled to a power input of the IHS;

a primary battery and a secondary battery; and

a switching apparatus for selectively coupling one of the primary and secondary batteries to the power input under the direction of control software in response to voltage at the power input detecting a fault condition, the switching apparatus coupling the selected battery to the power input independent of the state of charge of the selected battery, provided the selected battery exhibits a voltage greater than a predetermined threshold voltage.

2. The IHS of claim 1 wherein the primary battery is a dumb battery.

3. The IHS of claim 1 wherein the secondary battery is a dumb battery.

4. The IHS of claim 1 wherein the primary battery is a smart battery.

5. The IHS of claim 1 wherein the secondary battery is a smart battery.

6. The IHS of claim 1 wherein the switching apparatus includes a nonvolatile memory for storing the control software.

7. The IHS of claim 1 wherein the primary and secondary batteries have the same number of cells.

8. The IHS of claim 1 wherein the primary and secondary batteries have a different number of cells.

9. An information handling system (IHS) coupled to a docking station comprising:

a processor coupled to a power input of the IHS;

a primary battery and a secondary battery, the batteries being of different chemistries and cell stack configurations; and

a switching apparatus including;

a first diode switch between the primary battery and the power input;

a second diode switch between the secondary battery and the power input;

the switching apparatus selectively coupling one of the primary and secondary batteries to the power input under the direction of control software in response to voltage at the power input

detecting a fault condition, the switching apparatus coupling the selected battery to the power input independent of the state of charge of the selected battery, provided the selected battery exhibits a voltage greater than a predetermined threshold voltage;

a first bypass switch coupled across the first diode switch, the first bypass switch closing under direction of the control software to bypass the first diode when the primary battery is the selected battery; and

a second bypass switch coupled across the second diode switch, the second bypass switch closing under direction of the control software to bypass the second diode when the secondary battery is the selected battery.

10. A method of operating an information handling system coupled to a docking station comprising:

providing primary and secondary batteries to supply power to a power input of the information handling system;

selecting one of the primary and secondary batteries as a selected battery; and

switching the selected battery to couple to the power input independent of the state of charge of the selected battery, provided the selected battery exhibits a voltage greater than a predetermined threshold voltage, the switching being in response to the power input detecting a fault condition.

11. The method of claim 10 wherein the primary battery is situated in the information handling system.

12. The method of claim 10 wherein the secondary battery is situated in the docking station which is adapted to be coupled to the information handling system.

13. The method of claim 10 further wherein the switching is requested by control software within the information handling system.

14. The method of claim 13 wherein the control software instructs switching to couple the primary battery to the power output and in response the secondary battery is isolated from the power output.

15. The method of claim 14 further including coupling the primary battery to the power output subsequent to isolating the secondary battery from the power output.

16. The method of claim 15 including coupling the primary battery to the power output by a diode therebetween, this coupling being a hardware mode.

17. The method of claim 16 including bypassing the diode to reduce power loss, the bypassing being at the direction of control software, this bypassing being a software mode.

18. The method of claim 13 wherein the control software instructs switching to couple the secondary battery to the power output and in response the primary battery is isolated from the power output.

19. The method of claim 18 further including coupling the secondary battery to the power output subsequent to isolating the primary battery from the power output.

20. The method of claim 19 including coupling the secondary battery to the power output by a diode therebetween, said coupling being a hardware mode.

21. The method of claim 20 including bypassing the diode to reduce power loss, said bypassing being a software mode.

22. The method of claim 10 wherein the primary and secondary batteries are dumb batteries.

23. The method of claim 10 wherein the primary and secondary batteries are smart batteries.

24. A method of operating an information handling system (IHS) coupled to a docking station, the method comprising:

providing primary and secondary batteries to supply power to a power input of the IHS;

selecting one of the primary and secondary batteries as a selected battery;

switching the selected battery to couple to the power input via a diode therebetween, provided the selected battery exhibits a voltage greater than a predetermined threshold voltage, the switching being independent of the state of charge of the selected battery and being in response to the power input detecting a fault condition;

isolating the selected battery if the voltage of the selected battery is less than the threshold voltage; and

bypassing the diode upon command of control software after the diode has connected the selected battery to the power input.