Keep Your iPhone Alive With the Mophie Juice Pack

The iPhone3G is a terrific platform for GPS-enabled applications, and there are new location-based apps coming out every week. However, iPhone GPS and app usage drains battery power at a rapid pace. You may not even make it through a full day on a full charge if you use the iPhone's GPS and apps heavily. Enter the Mophie Juice Pack, which puts a powerful, rechargeable, supplemental battery into a protective iPhone case. Just charge up the Juice Pack, which comes with its own USB cable, and slide your iPhone into the case. Much neater than awkward dongle-style mobile chargers.

Mophie has offered a line of cases and battery packs for some time, and its newest introduction builds on the company's experience to create a versatile and very useful battery boost for the iPhone3G. Most appealing is its form factor - a slim, soft-grip case that snugly holds the iPhone and includes an Apple-compatible connector.

The Juice Pack may be charged separately, or with the iPhone inserted. You may simultaneously sync the iPhone and charge it while inserted in the Juice Pack (new for this version), a nice touch. A set of four tiny blue LED lights on the back of the Juice Pack indicates charge status. Push the charge-check button to see status. The Juice Pack is relatively light (3 ounces) and slim (approximately doubles the width of the iPhone). It's actually easier to grip and use the iPhone with the Mophie in place, but it feels bulkier in a pocket.

The Juice Pack has a set of cleverly designed openings to keep the microphone, speaker, camera, etc. accessible and uncovered. No iPhone capability is blocked by the Juice Pack. All of the iPhone functions worked normally during my tests.

The case doesn't protect the front of the iPhone, but that's not an issue for me, because I like to have the front open. Another minor negative, Mophie lists a limited life cycle for the Juice Pack: "rechargeable for over 500 cycles (full cycles, partial cycles don't count as full... charge your juice pack 10 percent of the way 10 times before it counts as a complete cycle.) Don’t be afraid to top it off! After 500 cycles, its fully charged capacity will be less than 75 percent of the capacity of when it's new," states Mophie literature.

Overall, the Juice Pack is a well-thought-out and well-designed juice boost for the iPhone3G, and more than doubles your time to play with all of the iPhone's features between charges.