Taken from : //www.macnn.com/reviews/mophie-juice-pack-for-iphone-3g.html

Mophie Juice Pack for iPhone 3G

February 22nd, 2009
A subtle but capable refresh of the Mophie Juice Pack.

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.

acoustics and the mini USB port

Although it looks on the surface as though it should block out sound, the Juice Pack is surprisingly loud. Very subtle scoops on the front channel both the microphone and speaker sound. Ringtones had the same volume as they did with a naked iPhone. Callers likewise didn't notice any conspicuous difference in voice quality.

While this absence of change is welcome, one important but equally useful change comes through the external connection: rather than simply put an Apple-standard Dock Connector on the outside, the company uses a mini USB jack. This does rule out using certain iPod accessories directly, but it also means that virtually any mini-to-full USB cable -- such as for a digital camera -- will work for charging and syncing. Travelers who've suddenly been at a loss for an official cable may consider this feature useful all by itself.

battery life and recharging

Of course, the central feature of the Juice Pack is the extended battery life, and it's here that it excels. We found that a moderate amount of use, including a few hours of heavier-duty tasks like Internet access, YouTube videos, 3G calls and music playback, still left the phone running entirely on the Juice Pack's built-in charge for nearly a whole day. The review unit was plugged in at 7PM on one day and didn't switch over to the iPhone's own battery until 4PM the next; as such, it's entirely possible that an average user could run an iPhone for about two days.

Time hasn't allowed for testing in harsher conditions, but we have reason to expect Mophie's claims for more non-stop use to be accurate. The company expects about 6 hours of extra 3G calling and data time as well as 8 hours of video. While there will likely be some fluctuation for those on the fringe of the network (where the radio has to boost reception power) or indulging in a heavy amount of Internet video streaming, even a conservative view would still add enough time that the most committed users could still last for a day on a charge. Those who regularly use iPhones for Internet radio or as a lifeline for work will be very happy.

The only suspicion is that standby time of 350 hours is optimistic: it's likely achievable, but certainly not with the iPhone in full 3G mode with Wi-Fi enabled.

When it comes time to recharge, the Juice Pack is fairly flexible and will charge both itself and the iPhone when plugged in. It also doesn't depend on being plugged into a main USB port and will gladly draw energy from a spare port on a keyboard or a computer display. Charging itself takes a long time, however. It took well under two hours to reach about half power, but it wasn't until closer to four that the Mophie pack said it was finished. Any buyer should be careful to keep the add-on charged if they think they may only need it in emergencies.

A back power indicator not unlike the one for Apple's own MacBook batteries lets you know how much energy the Juice Pack has of its own through a button press. It's appreciated and is also intelligent enough to show relative progress when the Juice Pack is recharging, though it's not very granular with just four lights to indicate status. However, it will flash to indicate its recharge progress, which can be helpful for those who need just a short extra charge before heading out the door.

wrapping up

It's evident that Mophie felt it hit the right blend of design considerations with the original Juice Pack, and the 3G model largely proves them right. There's a massive amount of extra battery life to be had even in casual use, and we could see the newer version being handy for those who simply don't like docking every day as much as those that would run out of battery life through heavy GPS or Internet use.

The added grip and extra weight also work in the accessory's favor. Anyone who has been paranoid about the iPhone's glossy plastic and comparatively modest heft will appreciate the ergonomics all by themselves.

Mophie's only real failing is its lack of ambition. As a near carbon copy of the old model, the 3G variant can't help but leave protective owners more than slightly nervous: a fall upside-down or against the sides could scratch the iPhone fairly easily, neither of which is especially acceptable for a $100 peripheral. There's also the question of the feature set. In contrast to alternatives from FastMac and others, here are no enhancements to the camera, and the USB port is only useful for charging the iPhone rather than powering a third-party device. Mophie's design is more compact as a result, particularly at the bottom where there's no large "chin," but it's a major consideration that can't be overlooked.

And there's also the question of whether it's the right Mophie model. As of this writing, Mophie had just recently unveiled the Juice Pack air. Although it will hold about a third less of a charge at 1,200mAh versus 1,800 for the full-size Juice Pack, it will also be much thinner and provide full protection for the top, all for about $20 less. While it's not due until the spring and may arrive just weeks before a likely iPhone refresh, the balance may be more alluring.

As such, we still recommend the current Juice Pack, but not unreservedly. It's well-made and well-designed, but those who want more protection or more features either have alternatives now or will have them soon.

- Adds a day of moderate use or a half-day of heavy use.

- Grippy, reassuring shell.

- Compact on the front.

- Both iPhone and battery pack charge over standard mini USB.

- Leaves significant portions of the iPhone exposed.

- Plain in features for the price.

- USB only works for the iPhone and case, not third-party gear.