mophie Juice Pack Air [$79.96 - iMore Store link] is the newer, sleeker model in town. We've tried out several battery extenders here on TiPb, and I've tried quite a few personally, but like the grail we keep looking for longer, better, and stronger power. Did I find it with the Juice Pack Air?
James has been talking the Air up for a while, but I wasn't sure about it. There are several variations in battery charger available for the iPhone, after all. First, form factor. Some chargers are modules that plug onto the bottom and while they can pack a punch, you have to be careful how you handle the iPhone when they're connected, lest they become rapidly unconnected. mophie makes the other kind, the case-style, and the Air -- as the name suggests -- is molded to be as thin and remain as pocketable as possible. In this, it succeeds brilliantly.
Some have complained that the Air's case-like form factor reduces their cell signal strength by a couple bars. I didn't experience that, though I'm in Canada and -- apologies to my long-suffering AT&T friends -- the iPhone is solid on our network.
The other variation is charging style. Some battery extenders charge via a dock port that makes them very handy since dock cables are ubiquitous and if you already have an AC adaptor, car adaptor, etc. they "just work" with those.
The mophie, by contrast, uses a USB micro-cable, but not micro-USB, which is always a concern (if your forget it, or lose it, your battery charger ain't getting charged).
Enough about what it is, what's important is how it works. I tested this one out on a weekend trip, and on several heavy-duty usage days. I also ended up testing it out when I negligently pocketed my iPhone while still recording video, leading it to discharge fairly rapidly.
And it worked well, pretty much in line with mophie's specs. It recharged my iPhone fairly close to full, and on one occasion recharged both mine and a friend's halfway during a 2 hour drive when a car charger failed on us.
So, bottom line, if you need extra power and still want something sleek enough to easily carry your iPhone easily in your pocket, (and your cell signal is typically strong), the mophie Juice Pack is well worth checking out.
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