Power distribution controller

1. An apparatus comprising:

a first power source configured to supply power to a first component and to a second component;

a second power source configured to supply power to the second component; and

a power distribution controller configured to set an upper limit of current from the first power source to the second component based on average level of charge at the second power source over a predetermined amount of time,

wherein the power distribution controller is further configured to set the upper limit of current supplied from the first power source to the second component such that current transferred between the first component and the second components is kept substantially equal to a current corresponding an average power consumption of the second component.

2. The apparatus of claim 1 , wherein the first component is a base of a laptop computer and the second component is a top of the laptop computer.

3. The apparatus of claim 1 , wherein the power distribution controller is further configured to update the upper limit of current from the first power source to the second component on a periodic basis.

4. The apparatus of claim 1 , wherein the power distribution controller is further configured to increase the upper limit of current from the first power source to the second component in response to a decrease in the average level of charge at the second power source.

5. The apparatus of claim 1 , wherein the power distribution controller is further configured to decrease the upper limit of current from the first power source to the second component in response to an increase in the average level of charge at the second power source.

6. The apparatus of claim 1 , wherein the power distribution controller is further configured to update the upper limit of current from the first power source to the second component at any given time t equal to sum of (1) a percentage change in the charge at the second power source in a predetermined time period preceding t multiplied by an empirically determined constant (k) and (2) currently set upper limit of current from the first power source to the second component.

7. The apparatus of claim 1 , wherein the power distribution controller further configured to update the upper limit of current from the first power source to the second component at any given time t equal to sum of (1) a function of percentage change in the charge at the second power source in a predetermined time period preceding t and (2) currently set upper limit of current from the first power source to the second component.

8. The apparatus of claim 7 , wherein the function is an empirically determined function being at least one of (1) an integrative function, (2) a differential function, (3) a quadratic function, and (4) a log function.

9. The apparatus of claim 1 , wherein the power distribution controller is further configured to increase the upper limit of current from the first power source to the second component if the charge level of the second power source is below a first predetermined level.

10. The apparatus of claim 9 , wherein the power distribution controller is further configured to set the first predetermined level to a charge level of the first power source if the charge level of the first power source is below a second predetermined level.

11. The apparatus of claim 1 , wherein the power distribution controller is further configured to set an upper limit of current from the first power source to the second component based on a historical value of charge at the second power source measured at a predetermined historic time.

12. A method comprising:

determining an average level of charge at a second power source over a predetermined amount of time, the second power source being configured to supply power to a second component;

determining an upper limit of current from a first power source to the second component based on the average level of charge at a second power source over a predetermined amount of time, the first power source being configured to supply power to a first component; and

limiting current drawn from the first power source to the second component to the upper limit of current from a first power source to the second component.

13. The method of claim 12 , further comprising updating the upper limit of current on a periodic basis.

14. The method of claim 12 , further comprising increasing the upper limit of current from the first power source to the second component in response to a decrease in the average level of charge at the second power source.

15. The method of claim 12 , further comprising decreasing the upper limit of current from the first power source to the second component in response to an increase in the average level of charge at the second power source.

16. The method of claim 12 , further comprising determining the upper limit of current from the first power source to the second component such that the current transferred between the first component and the second components is kept substantially equal to a current corresponding an average power consumption of the second component.

17. A power distribution controller comprising:

a memory;

one or more processing units; and

an upper limit determination module stored in the memory and executable by the one or more processor units, the upper limit determination module configured to set an upper limit of current supplied from a first power source to a component based on an average level of charge at a second power source over a predetermined amount of time and update the upper limit of current from the first power source to the second component at any given time t equal to sum of (1) a percentage change in the charge at the second power source in a predetermined time period preceding t multiplied by an empirically determined constant (k) and (2) currently set upper limit of current from the first power source to the second component.

18. The power distribution controller of claim 17 , further comprising a relative change determination module configured to increase the upper limit of current from the first power source to the component in response to decline in the average level of charge at the second power source.

19. The power distribution controller of claim 18 , wherein the relative change determination module is further configured to decrease the upper limit of current from the first power source to the component in response to increase in the average level of charge at the second power source.