My initial observations of battery life on the new iPhone 3G were very disappointing with the battery barely making it from morning until late evening. This is with moderate usage: email, browsing, Google maps, NetNewsWire, checking out the App Store, etc. I’ve experimented with a few tweaks over the past week to gauge the impact on battery life such as turning off Push, deactivating Location Services, lowering the brightness, etc.

The bottom line (for me) is that turning off 3G has made the biggest difference, by far. After a couple of days with 3G off, I am finding that my battery is at 50% at the end of an evening, rather than red-lining at less than 20%. Do I notice a big difference between EDGE and 3G? It’s noticeable, but not a huge difference. For me, using an RSS reader such as NetNewsWire dramatically reduces the amount of time I spend surfing my favorite sites for updates and wasting valuable battery life.

I’m curious to see what the consensus on battery life will be after people have the iPhone in hand for a few weeks.