Mophie is very much a veteran of iPhone battery packs, having built one for the original when the market was still largely untested. The Juice Pack for iPhone 3G is an opportunity for the company to take a definitive lead, and in many senses it's still one of the best -- but, as quickly becomes clear, it's a conservative approach that leaves room for improvement.

design and protection

Those who had the opportunity to try the original Juice Pack for the first-generation iPhone will find more than a little familiar: in fact, aside from the curvature needed to fit the iPhone 3G's tapered back, it may be hard to tell the difference. The most conspicuous change is the perceived build quality, which seems more refined versus the slightly rough layout of the original.

For those still new to the design, the Juice Pack is effectively a form-fitting sled: it's designed to stay attached to the iPhone as both a semi-permanent battery as well as a protective shell rather than connect only when absolutely necessary.

In the hand, it feels reassuring and comfortable; the whole surface has a very grippable texture, while a rubber strip on each side adds just that extra amount of resistance to prevent the iPhone from slipping out in casual use. It's not slim, however. The need to include a sizable battery nearly doubles the thickness of the device at its thickest point and could rule the pack out for those with tight or crowded pockets. There's also a tendency for the black surface to accumulate lint.

Thankfully, this does also add protection to the back, though the Juice Pack's central issue is that it doesn't protect enough. Much like the original, the 3G edition leaves both the upper sides and some of the back unnecessarily exposed; why leave the right side open in particular, when there's no hold switch or volume rocker to justify the move? Mophie's design decision is an instance of aesthetic symmetry seemingly getting in the way of pragmatic design; the sled should run up the entire back and cover up spaces that aren't going to be used.

And expectedly, the Juice Pack isn't designed to protect the screen, though this is forgivable given what it's meant to do; prospective owners should just be aware that all the padding won't protect against a face-first drop.

by Jon Fingas