Mophie Juice Pack Air and Helium: the extra battery life your iPhone 5 desperately needs

The Juice Pack Helium and the Juice Pack Air are pretty similar: both are sled-style cases that you slide the iPhone into. The cases essentially double the thickness of the iPhone, and add about 62 to 68 percent more weight to it. Both have soft-touch finishes, and on / off switches and capacity meters on their backs. The differences between the two are minimal: the Helium is ever so slightly thinner (0.04 inches) and lighter (0.24 ounces), but has less battery capacity (1,500mAh vs. 1,700mAh) than the Air. The Air also has better build quality, with pass-through style buttons for volume and power instead of the Helium’s simple cutaways.

Mophie says the Helium will get you 80 percent more battery life from your iPhone 5, or roughly an additional six hours of talk time before you need to plug it in. In my tests, the Helium was able to recharge the iPhone from zero to about 66 percent full before running out of juice. Though that's not quite up to Mophie’s claims, it's plenty enough to get most anyone through the day without having to worry about their iPhone dying during happy hour at the bar. You won’t be going a solid two days with heavy usage on the Helium, but you can take full advantage of your iPhone’s features without being concerned too much about the battery dying on you.

Similarly, Mophie claims that the Air case will net 100 percent more battery life, or an additional eight hours of talk time. As with the Helium, my tests with the Air didn't quite match Mophie's claims — a full charge from zero brought the iPhone to about 80 percent full — but it kept me off an outlet the entire day, and even into the next day if I played my cards right.

Both cases suffer from the same drawbacks: the way you slide the phone into the case can leave marks and scuffs on the iPhone (and sure enough, I noticed some blemishes on my black iPhone 5 after using them), and the two halves of the cases can be really hard to separate, making it a pain to take the phone in and out of the case. That wouldn't be so much of a problem, except that the Juice Packs' micro-USB ports don't allow for syncing or data transfer — they just charge the battery. That means whenever you need to sync your phone with your computer over USB, or if you tether your iPhone over USB (which I do often), you have to pry the case off the phone. Also, because the headphone jack is located on the bottom of the iPhone 5, the cutaway to access it through the Juice Packs is pretty deep. Mophie provides an extender with the cases to enable headphone cables to reach the deeply recessed port, but I didn't have any trouble using the case with a number of headsets and no extender, including Apple's EarPods. If you have headphones with a right-angle plug on the end, prepare to carry around that silly adapter.