Abstract: A method and apparatus for preventing cross-talk in systems employing one-to-many magnetic resonance power transfer are disclosed. A method may include powering down a magnetic resonance coil, receiving an identifier from a power receive unit located at a predetermined charging location using close-range wireless communication, powering up the coil, receiving information from the power receive unit using short-range wireless communication addressed with the identifier, transferring energy from the power transfer unit to the power receive unit using the coil, and displaying an indication of the status of the battery to a display communicatively coupled to the power transfer unit. The predetermined location may be among a plurality of locations for a plurality of power receive units in proximity to the power transfer unit and the information received from the power receive unit may be indicative of a status of a battery electrically coupled to the power receive unit.

Abstract: A method and apparatus for preventing cross-talk in systems employing one-to-many magnetic resonance power transfer are disclosed. A method may include powering down a magnetic resonance coil, receiving an identifier from a power receive unit located at a predetermined charging location using close-range wireless communication, powering up the coil, receiving information from the power receive unit using short-range wireless communication addressed with the identifier, transferring energy from the power transfer unit to the power receive unit using the coil, and displaying an indication of the status of the battery to a display communicatively coupled to the power transfer unit. The predetermined location may be among a plurality of locations for a plurality of power receive units in proximity to the power transfer unit and the information received from the power receive unit may be indicative of a status of a battery electrically coupled to the power receive unit.

Abstract: A battery pack having at least one electrochemical cell and a temperature dependent boost circuit is provided. Since the cell voltage is diminished at low temperatures, and as portable electronic devices typically have a minimum operational voltage limit, the boost circuit is actuated at low temperatures to step up the voltage from the cell to the electronic device. In one embodiment, the boost circuit is coupled serially between the cell and the output terminals of the battery pack. In parallel with the boost circuit is a boost bypass circuit. A controller senses the temperature of the battery pack from a temperature sensor, like a thermistor. When the temperature falls below a predetermined minimum temperature threshold, the controller actuates the boost circuit, thereby increasing the output voltage of the pack. Concurrently with the actuation of the boost circuit, the controller causes the boost bypass circuit to enter a high impedance state.

Abstract: A method for determining time to completion is provided for a battery charging system. The system preferably includes a charger having a microprocessor and a battery with a memory. The memory includes information about the battery, including battery identifiers, charging states, charging procedures and charging termination information. The charger reads this battery and then determines the charging states associated with the battery. The charger then determines the present state of charge, and calculates a time to completion for that state. The charger then determines times to completion for the remaining charge states, optionally compensating for self discharge within the battery. A total time to completion is determined by summing the times to completion for the respective charging states.