Hey Siri in iOS 8 works only if you connect your iPhone or iPad to the power source, but here is a trick you can use to force this hands-free voice-recognition tool to wake up and listen to you all the time.
In short, you will have to plug in your device to the power source only once, and then you can use Hey Siri without the power source. Follow these steps:
- Step 1: Activate both Siri and Hey Siri.
How to do it: From your iPhone/iPad, go to General -> Settings to enable Siri and Hey Siri [Complete Tutorial].
- Step 2: Charge your iOS device.
How to do it: Connect the charger (USB cable) to the charging port of your iPhone/iPad. You can also plug your device to your computer via USB cable to begin charging the device.
- Step 3: Talk to Siri or Hey Siri
How to do it: This step requires you to open Siri and say any command. Press and hold the Home button to launch Siri. You can also trigger Hey Siri by saying the command “Hey Siri” (without having to press the Home button).
- Step 4: Remove power source
How to do it: Just unplug your iPhone/iPad. Remember to keep Siri turned ON – do not go back to the homescreen.
- Step 5: Speak to Hey Siri
How to do it: Now you can speak to Hey Siri without plugging your iOS device into AC power source.
Example: Using Hey Siri to play movie trailers (not seen in pic: the iPhone is not connected to a power source):
Remember: Activating voice-recognition tools like Hey Siri that runs in the background drains the battery life of your iOS device.