A friend and I were having a discussion about the best way to maintain an iphone's (and other cell phone's) battery life. Her husband suggests that one should always run the battery down until it's almost dead and then charge it; the thought being a battery has just so many charges in it and you want to spread them out. I, on the other hand, am so afraid of running out of battery, I put my phone on the charger whenever I am near one. In fact, it's always charging when I am home. It rarely every goes below 40% unless I'm out the in the wild and most days no less than 80 or 90%. But now that my new iPhone is coming, I thought this was a good time to check it out. So... Run it down or keep it charged? Which is better to extend the life of one's cell phone battery?