Apparatus, methods, and systems according to which shutdown features are provided to battery-powered electronics. An automatic shutdown device detects periods in which the battery-powered electronics are motionless using a sensor and, based on such detection, disconnects the battery from the battery-powered electronics using an electronic switch, rendering the battery-powered electronics inoperable. In addition, the automatic shutdown device is able to reenergize the battery-powered electronics using the electronic switch once motion is detected by the sensor so that the battery-powered electronics can resume normal operations. In several embodiments, the battery-powered electronics include a keyless fob associated with a vehicle and the automatic shutdown device is part of a vehicle theft prevention system.