I've been using Navigon as my replacement GPS for work on my iPhone 4. My drive time from one location to the next is usually 15-30min and I have about 3-5 stops a day. I connect my iPhone to the car for charging. By me doing that am I damaging the battery life as I am not doing a full charge everytime?? I've heard to drain the battery to 20% every once in awhile to recalibrate the battery or how the iPhone detects the battery life...or something like that?? Thanks.