Control of output power of a battery charger for charging a battery of an electronic device from an energy source

1. An electronic device comprising:

a battery charger to receive a voltage from an energy source, and to provide an output power; and

a controller to:

receive a voltage value of the energy source;

receive a current value from the battery charger;

determine a present power value based on the received voltage value and the received current value;

compare the present power value with a previous power value to determine if a difference between the present power value and the previous power value is greater than a threshold; and

if the difference is greater than the threshold, provide at least one control signal to the battery charger to change the output power of the battery charger.

2. The electronic device of claim 1 , wherein the battery charger is to increase a current limit of the battery charger based on the determined present power value.

3. The electronic device of claim 1 , wherein the battery charger is to decrease a current limit of the battery charger based on the determined present power value.

4. The electronic device of claim 1 , wherein the energy source is at least one of a solar power source, a mechanical power source, a photovoltaic power source, a thermal power source, a radio frequency power source, a vibration power source, a biomechanical source or a fuel cell.

5. A method of an electronic device comprising:

receiving, at a charger, a voltage from an energy source;

providing an output power from the charger;

receiving, at a controller, a voltage value of the energy source;

receiving, at the controller from the charger, a current value to indicate an input current to the charger;

determining, at the controller, a present power value based on the received voltage value and the received current value;

determining if a difference between the present power value and a previous power value is greater than a threshold;

if the difference is greater than the threshold, providing at least one control signal to the charger based on the determined present power value; and

changing an output power of the charger based on the at least one control signal.

6. The method of claim 5 , wherein changing the output power includes increasing a current limit of the charger based on the determined present power value.

7. The method of claim 5 , wherein changing the output power includes decreasing a current limit of the charger based on the determined present power value.

8. The method of claim 5 , wherein the energy source is at least one of a solar power source, a mechanical power source, a photovoltaic power source, a thermal power source, a radio frequency power source, a vibration power source, a biomechanical source or a fuel cell.

9. The method of claim 5 , wherein changing the output power is based on a plurality of bits received from the controller.

10. The method of claim 5 , further comprising providing a control signal to a switch of at least one current sensing resistor based on the received voltage value and the received current value.

11. A machine-readable medium comprising one or more instructions that when executed on a controller to perform one or more operations is to:

determine a present power value of a charger based on a voltage value received from an energy source and a received current value that corresponds to an input current to the charger;

determine that a difference between the present power value and a previous power value is greater than a threshold; and

responsive to the determination that the difference is greater than the threshold, provide at least one control signal to the charger based on the determined present power value to change an output power of the charger.

12. The machine-readable medium of claim 11 , wherein the at least one control signal is to increase a current limit of the charger based on the determined present power value.

13. The machine-readable medium of claim 11 , wherein the at least one control signal is to decrease a current limit of the charger based on the determined present power value.

14. An electronic device comprising:

first means for providing an output power;

second means for:

determining a present power value based on a voltage value received from an energy source and a received current value that corresponds to an input current to the first means; and

determining whether a difference between the present power value and a previous power value is greater than a threshold; and

third means for, if it is determined that the difference is greater than the threshold, providing at least one control signal to change the output power.

15. The electronic device of claim 14 , wherein the first means for providing at least one control signal is to increase a current limit based on the determined present power value.

16. The electronic device of claim 14 , wherein the first means for providing at least one control signal is to decrease a current limit based on the determined present power value.