Portable battery pack for wirelessly charging body-worn devices through clothing

A wireless power transfer system, comprising:

• a portable battery pack including:
• a first housing having a first mating surface;
• a first permanent magnet disposed on the first mating surface for coupling with a second permanent magnet on a portable electronic device;
• first battery cells secured within the first housing;
• a first printed circuit board (PCB) secured within the first housing, the first PCB including:
• a power amplifier coupled to the first battery cells;
• a rectifier and battery charger coupled to the first battery cells;
• a connector with metal contacts coupled to the rectifier and battery charger, the connector configured for connecting to an input power source;
• and
• a transmitter coil coupled to the power amplifier through transmitter resonant capacitors;
• a portable electronic device including:
• a second housing having a second mating surface;
• the permanent magnet disposed on the second mating surface for coupling with the first permanent magnet disposed on the first mating surface of the portable battery pack;
• a second battery included in the second housing;
• and
• a receiver coil included in the second housing and coupled to the second battery, wherein the first mating surface and the second mating surface have the same dimensions, such that there is no overhanging portions of the first housing or the second housing when the portable battery pack and the portable electronic device are joined in a mated configuration by the first and second permanent magnets.