This weekend, in my first trip with the app outside of SoCal, I drove from Long Beach to Las Vegas in the mid afternoon (meaning 100°+ weather the whole way), using Navigon and the iPod together. It took me just about four hours, including one ten minute stop for my dog to do his business, and I ended up in Vegas with a fully charged iPhone.
I have a dedicated USB charger that connects through my stereo, and I don't know if that matters, but I do know that I was completely happy with both the navigation and the performance as a whole. It didn't lose signal once, it warned me at the correct times, and generally performed significantly better than my stand-alone Magellan.
Do you have a 3G or a 3Gs? My Navigon on the 3Gs is constantly loosing signal. Think theres something up with my hardware....
