There’s a lot of negative press around the iPhone 3G’s battery life. I don’t own a 3G yet, but I’ve carried my trusty 2G for over a year now. Yes, I was one of the Fan-Boys who payed $600 and waited in line for an 8-Gig iPhone. At least I got $100 back from Apple (it’s better than nothing).

There are plenty of battery saving tips published already. I’m not going to re-hash those here. I actually get more than a day out of my iPhone 2G with normal use. That’s as good as any smart phone I’ve ever owned.

I’m concerned about heavy-use days, however. With iPhone OS 2.0 and the App Store, there are a lot more heavy-use days.

So, I bought a mophie extended battery. I heard about the mophie on MacBreak Weekly. If you are a Mac owner and don’t listen to MBW, run, don’t walk to iTunes and subscribe immediately.

The mophie is an extended battery in the form of an iPhone case. It connects via the dock connector and charges the iPhone as if it were plugged into a wall power adapter.

The mophie adds some bulk to the iPhone. When connected, my iPhone feels similar in size to the old Treo 650 I used to carry around.

Actually, the Treo is thicker in some spots. I carried that phone for two years, so the iPhone with a mophie used occasionally is definitely worth the extra bulk.

One nice feature about the mophie is the cut-out design for the iPhone speaker and mic. It simulates what I often find myself doing with my hand. That is: making a cup shape around the speaker so that I can hear it better. With the mophie attached, the speaker volume is much better.

The price is a little steep at $100 and there isn’t an iPhone 3G version yet. According to the mophie web site, they will begin shipping the 3G version in late September. Given the decreased battery life with 3G and GPS, the mophie will probably be an essential accessory when I upgrade.