Systems and methods for wireless charging

An portable electronic device comprising:

• a battery;
• a wireless power receiver;
• a tunable power electronic circuit connected between the battery and the wireless power receiver;
• a wireless communication receiver;
• a 3-axis accelerometer;
• a 3-axis magnetometer;
• a 3-axis gyroscope;
• and
• a controller configured to determine an orientation of the wireless power receiver with respect to a wireless power transmitter based on signals from the wireless communication receiver, 3-axis accelerometer, 3-axis magnetometer and 3-axis gyroscope and connected to tune the tunable power electronic circuit based on the determined orientation.

A method for wirelessly charging a portable electronic device, the method comprising:

• providing a wireless power transmitter at a fixed location;
• providing a wireless power receiver in the portable electronic device;
• determining a relative position and orientation of the wireless power receiver in relation to the wireless power transmitter;
• determining a mutual inductance between the wireless power receiver and the wireless power transmitter based on the relative position and orientation;
• determining a desired resistance of a power electronic circuit connected to the wireless power receiver based on the mutual inductance;
• and
• adjusting an effective resistance of the power electronic circuit to match the desired resistance.