"Your mobile phone is lying to you. So is your laptop. And not just when they whisper to you in the night.Mobile phones, and most modern laptops, have signal strength and battery life displays. One or both of these displays has probably been the focus of all of your attention at one time or another.Neither display is actually telling you what you think it's telling you."
Here is an interesting article on what your battery indicator and signal strength icons on your phone are telling you. It explains why when I am sometimes in an area that has "full signal strength" that calls are dropped or of really bad quality.