Mophie Juice Pack Air not that airy, but brings the juice

Who wants to lug around a bulky battery extender for the iPhone or iPod touch when you can get a Mophie Juice Pack Air? The idea of the product is to provide an auxiliary battery hidden inside an attractive case, and Mophie has done an admirable job of doing just that. We tucked our iPhone 3GS (also works with the 3G) into one of these shiny black cases, and did an informal endurance test over the weekend, marveling at the long battery life of our iPhone when wearing this shiny battery-packed jacket.

You can set the Juice Pack to deplete itself first, or let the iPhone run out of battery power and then automatically switch over to it. You can also charge your iPhone and the Juice Pack at the same time, by plugging in the Juice Pack while the iPhone's inside it. It's supposed to also sync the iPhone when charging it this piggyback way, but unfortunately, I got error message when I tried to do that. And too bad the Juice Pack uses an oddball micro USB plug to hook up for charging.

The bottom line: This thing makes your iPhone keep on going and going. Compared to the iPhone's paltry battery life on its own, this baby makes the iPhone feel like it could go on forever. It would be great for road warriors and tradeshow denizens.

The downside? The thing is just too damn big. Even though it's called the Juice Pack "Air," that air must be the kind you'd find in a sweaty, smoky jazz club — heavy and thick. The 2.2-ounce Juice Pack makes the iPhone weigh 7.1 ounces, which feels a whole lot heavier than it does naked. When you have it in your pocket, it starts pulling your pants down. And it makes the iPhone feel at least twice as thick.

The Juice Pack lets you add lots of battery life to your iPhone, but as far as battery extenders go, you'll be substituting that clunky auxiliary battery hanging off the bottom of the iPhone with a clunky extender surrounding it. Take your pick. Besides the few flaws I've mentioned, Juice Pack looks great (while not exactly "air-y"), works well as a protective case, and fixes the biggest drawback of the iPhone, its laggard battery life. With the Mophie Juice Pack Air, I used the iPhone for three days without a charge, instead of sticking with my customary daily charge routine. If you're on the road a lot, or working long days, it's well worth its $80 price.

Mophie Juice Pack Air