A system, comprising: a mobile device, comprising: a primary antenna; and a mobile device power source configured to supply power to the primary antenna; an article of apparel, comprising a textile material: a mobile device holder, coupled to the textile material, configured to secure the mobile device with respect to the article of apparel; and an electrical system, including: an antenna (102, 500A, 500B), configured to communicatively couple with the primary antenna of the mobile device, positioned in relation to the holder, and positioned to be in substantial alignment with the primary antenna of the mobile device such that the primary antenna and the antenna are able to communicate with one another when the mobile device is secured in the mobile device holder; a power supply, coupled to the antenna, configured to output power based on a current generated in the antenna when communicatively coupled with the primary antenna; a controller, coupled to the power supply, operable based on the power as output by the power supply; and a sensor, coupled to the textile material, communicatively coupled to the controller via a conductor, configured to detect a sensor condition and output a sensor signal when powered by the power output by the power supply. a mobile device, comprising: a primary antenna; and a mobile device power source configured to supply power to the primary antenna; a primary antenna; and a mobile device power source configured to supply power to the primary antenna; an article of apparel, comprising a textile material: a mobile device holder, coupled to the textile material, configured to secure the mobile device with respect to the article of apparel; and an electrical system, including: an antenna (102, 500A, 500B), configured to communicatively couple with the primary antenna of the mobile device, positioned in relation to the holder, and positioned to be in substantial alignment with the primary antenna of the mobile device such that the primary antenna and the antenna are able to communicate with one another when the mobile device is secured in the mobile device holder; a power supply, coupled to the antenna, configured to output power based on a current generated in the antenna when communicatively coupled with the primary antenna; a controller, coupled to the power supply, operable based on the power as output by the power supply; and a sensor, coupled to the textile material, communicatively coupled to the controller via a conductor, configured to detect a sensor condition and output a sensor signal when powered by the power output by the power supply. a mobile device holder, coupled to the textile material, configured to secure the mobile device with respect to the article of apparel; and an electrical system, including: an antenna (102, 500A, 500B), configured to communicatively couple with the primary antenna of the mobile device, positioned in relation to the holder, and positioned to be in substantial alignment with the primary antenna of the mobile device such that the primary antenna and the antenna are able to communicate with one another when the mobile device is secured in the mobile device holder; a power supply, coupled to the antenna, configured to output power based on a current generated in the antenna when communicatively coupled with the primary antenna; a controller, coupled to the power supply, operable based on the power as output by the power supply; and a sensor, coupled to the textile material, communicatively coupled to the controller via a conductor, configured to detect a sensor condition and output a sensor signal when powered by the power output by the power supply. an antenna (102, 500A, 500B), configured to communicatively couple with the primary antenna of the mobile device, positioned in relation to the holder, and positioned to be in substantial alignment with the primary antenna of the mobile device such that the primary antenna and the antenna are able to communicate with one another when the mobile device is secured in the mobile device holder; a power supply, coupled to the antenna, configured to output power based on a current generated in the antenna when communicatively coupled with the primary antenna; a controller, coupled to the power supply, operable based on the power as output by the power supply; and a sensor, coupled to the textile material, communicatively coupled to the controller via a conductor, configured to detect a sensor condition and output a sensor signal when powered by the power output by the power supply.