There seems to be a little confusion about the working, pairing and connection of BT. I'm going to talk about Apple BT. I own one so I can tell you how it really works, not just how it should work. Since the Apple BT was built for the iPhone it has some cool features like auto-pairing and it's own icon complete with BT battery level in the iPhone display.
The Apple BT is dedicated to the iPhone. Really dedicated. As pointed out elsewhere here, don't even thing of connecting the Apple BT to something else if there's an iPhone within 30 feet of it. It has a tendency to unpair from any other device and pair with the iPhone. Not every BT headset will play this well with your iPhone, so don't expect everything mentioned here to happen with a third party set:
- When the Apple BT and the iPhone are in the dual dock. They re-pair. This pretty much guarantees the set will work 100% of the time.
- When you remove the BT from the dock, it often has been reset to off during the charge. I don't use the LED on the BT for reference that much. I usually put it in my ear and tap the button on the back of the BT. If you get a beep you're in business. If you hear nothing it means the BT is off. Hold the button until you hear four ascending tones. Now you're in business.
- Anytime the iPhone and BT are more than 30 ft (10 meters) apart the connection will be lost. So if you leave your BT in the car, it's a good idea to reconnect when you get back in. Just tap the button. If listening you'll hear a beep. If looking at the BT you'll see a green LED flash. Or just look at the iPhone screen when connecting, the BT symbol will flash and then the headset icon will show on the top right next to your iPhone battery gauge. All is set.
- Should you forget to reconnect you may find the BT not responsive when you get a call. Don't start tapping the button like crazy. This won't connect it. Tap the button once. This is usually all it takes. After a few seconds the phone will answer. If you hear more than two rings in the BT, tap again.
- If you want to switch to the BT headset while in the middle of a call, just put the BT in your other ear and press the button once. If no response wait at least two seconds and press again.
