battery life and recharging

While the tendency is towards battery life über alles in most iPhone battery packs, mophie has consciously avoided this with the Air and readily admits as much: it's a hard shell case that just happens to have enough extra battery to keep a handset running longer each day.

With this in mind, the Air is still somewhat disappointing. From a full charge, the slim Juice Pack gave out in about three hours after a mixture of 3G and Wi-Fi browsing, music and short phone calls. Even though most of this was demanding, the test fell significantly short of mophie's claimed 4.5 extra hours of pure 3G browsing, let alone the extra time afforded by calls and Wi-Fi data. We hope this was more an exception than the rule, but as-is won't compare well to the full Juice Pack's ability to run for several hours at a time and effectively granting an extra day of battery life for moderate iPhone users.

Filling the Juice Pack Air back up takes roughly the same time: that is, it's typical but slow. The halfway point arrives quickly when charging the case alone through a computer's powered USB port, but as with most lithium-ion batteries, the rate of charge quickly slows down the closer you approach a full charge. It took a total of just over four hours to have a complete battery. Frequent flyers and others who need a constant charge should definitely consider toting either their notebooks or their iPhone AC adapters and prepare to start recharging immediately whenever the battery is either low or drained out; it won't be possible to get a practical emergency charge.

wrapping up

It may sound like we dislike the Juice Pack Air, but that's not the case; the top protection, slimmer profile and price could make it a great fit for anyone who wants both casing and battery but something that can still fit in a (reasonably sized) pocket. We wish it had a screen protector, but few guards outside of flip cases and sleeves truly offer enough front protection regardless, and not everyone likes those form factors. Compared to other competitors, this newest entry does an excellent job of preserving audio quality.

The real concern is the sheer number of qualifiers attached to recommending the Air over its thicker sibling. As of this writing, there's only a $20 gap between the two mophie cases; given that the Air itself starts at $80, it's not hard to quickly rationalize jumping to the regular Juice Pack for the greatly improved battery life or the easier-to-hold surface. The latter's use of mini USB also simplifies recharging: any A-to-B USB cable from a camera or printer will do, while the Air's micro USB isn't proprietary but also isn't as ubiquitous, either.

Whether you enjoy the Air consequently hinges on just how you use it. If it's simply to provide enough extra time for calls or Internet access after the workday is over, the smaller design works beautifully and saves some money in the bargain. But if you're the sort who regularly spends hours at the airport waiting for connecting flights or use your iPhone so often that it often needs a recharge in mid-day, the $100 model is undoubtedly the better option.

by Jon Fingas