Using Navigon in 3D without a charging cable, the iPhone 4s will last only about 1 hour on a full charge (the power drain is extraordinary). With the cable plug

Using Navigon in 3D without a charging cable, the iPhone 4s will last only about 1 hour on a full charge (the power drain is extraordinary). With the cable plugged into the car, I can navigate indefinitely. If I start out with a drained battery, I can plug it in the car for Navigon, and when I arrive at the destination, the battery is always fully charged (for trips > 1hr).