An environmentally sealed electronic device with an internal activation circuit that does not require a constant interrogation signal to maintain power to its internal circuitry. The electronic device includes sensor circuitry for gathering or sensing data; an internal battery for powering the sensor circuitry; and an internal activation circuit for activating the sensor circuitry. The sensor circuitry may include a temperature sensor, a location sensor, a signal sensor, a sound detector, a motion sensor, or any other device that senses or gathers data. The battery may be any type of energy storage device such as a lithium or alkaline battery. The activation circuit includes a receiver for receiving a radio frequency signal from an external source and a switch for connecting the battery to the sensor circuitry in response to the receiver. The switch is operable to maintain connection of the battery to the sensor circuitry after the radio frequency signal ceases.