Information handling system with battery protected from non-permanent failures

• US 20060108982A1
• Filed: 11/24/2004
• Published: 05/25/2006
• Est. Priority Date: 11/24/2004
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Sultenfuss, Andrew T., Daou, Youssef
• Granted Patent: US 7,538,519 B2
• Time in Patent Office: Days
• US Class Current: 320/116
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence

Abstract

In a method and system for protecting a battery being charged by an electrical device, a current flowing through a cell stack of the battery is measured. If the measured current is greater than a predefined value the battery is isolated from the device. If subsequent current measurements made within a predefined time interval indicate that the measured current is less than or equal to the predefined value then the battery is recoupled to the device. If the measured current remains greater than the predefined value during the predefined time interval then a fuse is blown and the battery is disabled.

Claims

1. A battery coupled to an electrical device via a positive and negative battery terminals, the battery comprising:

a cell stack operable to store a charge received through the battery terminals from the device;

a sense resistor for measuring a current flowing through the cell stack, wherein the sense resistor is electrically coupled to the stack;

a ground switch operable to control the current; and

a controller operable to control the ground switch in response to receiving an input indicative of the current, wherein the ground switch is operable to interrupt the current flowing to the device in response to the current being greater than a predefined value and enable the current flowing to the device in response to the current being less than or equal to the predefined value during a predefined time interval.

2. The battery of claim 1, comprising:

a charge switch operable to control the charge in response to receiving a charge enable control signal from the controller, wherein the charge switch is coupled in between the cell stack and the positive battery terminal.

3. The battery of claim 2, wherein the charge switch is disabled in response to the current being greater than the predefined value and enabled in response to the current not being greater than the predefined value during the predefined time interval.

4. The battery of claim 2, wherein the controller is operable to open a fuse device coupled in series between the charge switch and the cell stack in response to the current being greater than the predefined value during the predefined time interval.

5. The battery of claim 4, wherein a non-transient failure causes the current to be greater than the predefined value during the predefined time interval, wherein the battery is disabled in response to the fuse device being opened.

6. The battery of claim 1, wherein a transient failure event causes the current to be greater than the predefined value during a portion of the predefined time interval and a removal of the transient failure event within the predefined time interval causes the current not to be greater than the predefined value during another portion of the predefined time interval.

7. The battery of claim 6, wherein the transient failure event is caused by an electrical noise.

8. The battery of claim 7, wherein the noise is generated due to electromagnetic interference (EMI).

9. The battery of claim 7, wherein the noise is generated due to radio frequency interference (RFI).

10. The battery of claim 1, wherein the predefined time interval is less than a synchronous time interval frame defined for a system management bus (SMBus) communication.

11. The battery of claim 1, wherein the ground switch is coupled in series between the sense resistor and the negative battery terminal.

12. The battery of claim 1, wherein the ground switch is operable to control the current during a discharge mode of the cell stack.

13. A method for protecting a battery being charged by an electrical device, the method comprising:

measuring a current flowing through the battery;

determining whether the current is above a predefined value;

isolating the device from the battery in response to the current being above the predefined value;

determining whether the current remains above the predefined value during a predefined time interval; and

recoupling the device to the battery in response to the current not being above the predefined value during the predefined time interval.

14. The method of claim 13, further comprising:

disabling the battery in response to the current being above the predefined value during the predefined time interval.

15. The method of claim 14, wherein the disabling of the battery includes blowing a fuse to interrupt the current.

16. The method of claim 13, wherein the isolating of the device from the battery includes opening a ground switch to interrupt the current.

17. The method of claim 16, wherein the recoupling includes closing the ground switch.

18. The method of claim 13, wherein the measuring of the current occurs at a selectable sampling frequency, wherein the sampling frequency varies approximately between 1 millisecond and 10 seconds.

19. An information handling system (IHS) comprising:

a processor; and

a power supply operable to provide power to the processor, wherein the power supply includes;

a charger operable to provide a charge; and

a battery operable to receive the charge from the charger via a pair of terminals, wherein the battery includes;

a cell stack operable to store the charge received from the charger through the terminals;

a sense resistor for measuring a current flowing through the cell stack, wherein the sense resistor is electrically coupled to the stack;

a ground switch operable to control the current; and

a controller operable to control the ground switch in response to receiving an input indicative of the current, wherein the ground switch is operable to interrupt the current flowing to the charger in response to the current being greater than a predefined value and enable the current flowing to the charger in response to the current being less than or equal to the predefined value during a predefined time interval.

20. The system of claim 19, further comprising:

a charge switch operable to control the charge in response to receiving a charge enable control signal from the controller, wherein the charge switch is coupled in between the cell stack and a positive terminal of the pair of terminals.

21. The system of claim 20, wherein the controller is operable to open a fuse device coupled in series between the charge switch and the cell stack in response to the current being greater than the predefined value during the predefined time interval.