Method for determining residual battery charge

1. A method for determining a residual charge on a battery within an electronic device, comprising:

applying a current pulse to the battery resulting in a voltage at a first time;

determining first and second delta voltages measured from the voltage, at first and second delta times measured from the first time;

determining regression equation coefficients from the first and second delta voltages and first and second delta times; and

applying the regression equation coefficients to a database for determining the residual charge.

2. The method of claim 1 wherein the determination of the regression equation coefficients comprises regression analysis.

3. The method of claim 2 wherein the regression analysis comprises solving a system of two equations ΔV 1 =(α)1n(1+Δt 1 /ε) and ΔV 2 =(α)1n(1+Δt 2 /ε) to determine α and ε, where α is related to the voltage drop, ε is related to the time of the voltage drop, ΔV 1 is the first delta voltage, ΔV 2 is the second delta voltage, Δt 1 is the first delta time, and Δt 2 is the second delta time.

4. The method of claim 1 wherein the delta voltages and delta times are determined from a delay in time from the first time.

5. The method of claim 1 wherein the first time occurs after the application of the current pulse to allow for a voltage drop due to internal resistance.

6. The method of claim 1 wherein the first time occurs subsequent to the current pulse being applied.

7. The method of claim 1 wherein the electronic device is a mobile communication device and applying a current pulse comprises answering a call.

8. The method of claim 1 wherein the applying a current pulse comprises turning on or off a circuit of the electronic device.

9. A method for determining a residual charge on a battery within an electronic device, comprising:

connecting a load to the battery;

measuring a first voltage on the battery at a first time;

measuring additional voltages on the battery at additional times subsequent to the first time;

determining delta times by subtracting the first time from each of the additional times;

determining delta voltages by subtracting each of the additional voltages from the first voltage, wherein each of the delta voltages correspond to one of the delta times;

determining regression equation coefficients from regression analysis of the delta voltages and delta times; and

applying the regression equation coefficients to a database for determining the residual charge.

10. The method of claim 9 wherein the regression analysis comprises solving a system of N equations, where N is equal to the number of delta voltages available and is greater or equal to 2, based on the regression equation model ΔV=ƒ(Δt, a 1 ,a 2 , . . . , a N ), where ΔV is a function of Δt and N coefficients (a 1 , a 2 , . . . , a N ), wherein the values for each delta voltage and delta time are respectively substituted for ΔV and Δt in the equation to determine all N coefficients (a 1 , a 2 , . . . , a N ).

11. The method of claim 9 wherein the delta voltages and delta times are determined from a delay in time from the first time.

12. The method of claim 9 wherein the first time occurs after the connecting of the load to allow for a voltage drop due to internal resistance.

13. The method of claim 9 wherein the first time occurs after the load is connected.

14. The method of claim 9 wherein the electronic device is a mobile communication device and connecting a load comprises answering a call.

15. The method of claim 9 wherein the connecting a load comprises turning on or off a circuit of the electronic device.

16. A method for determining a residual charge on a battery within an electronic device, comprising:

connecting a load to the battery;

measuring a first voltage on the battery at a time t 1 ;

measuring a second voltage on the battery at a time t 2 ;

measuring a third voltage on the battery at a time t 3 ;

determining a first delta voltage from the second voltage minus the first voltage;

determining a second delta voltage from the third voltage minus the first voltage;

determining a first delta time from the times t 2 minus t 1 ;

determining a second delta time from the times t 3 minus t 1 ;

determining regression equation coefficients by regression analysis of the first and second delta voltage and first and second times; and

applying the regression equation coefficients to a database for determining the residual charge.

17. The method of claim 16 wherein the regression analysis comprises solving a system of equations based on the equation ΔV=(α)1n(1+Δt/ε) wherein the values for each delta voltage and delta time are respectively substituted for ΔV and Δt, to determine α and ε, where α is related to the voltage drop, and ε is related to the time of the voltage drop.

18. The method of claim 16 wherein the delta voltages and delta times are determined from a delay in time from the first time.

19. The method of claim 16 wherein the time t 1 occurs after the load is connected to allow for a voltage drop due to internal resistance.

20. The method of claim 16 wherein the time t 1 occurs after the load is connected.

21. The method of claim 16 wherein the electronic device is a mobile communication device and connecting a load comprises answering a call.

22. The method of claim 16 wherein the connecting a load comprises turning on or off a circuit of the electronic device.