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Computerized Investing > May 5, 2012

mophie juice pack plus—iPhone 4 & 4S Battery Case

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by Wayne A. Thorp, CFA

After losing my last cell phone to a catastrophic drop a year ago, I upgraded to an iPhone 4S. Wanting to protect my investment, I have tried out several cases over the last several months. My favorite, thus far, has been the Otterbox Defender, which offers heavy-duty protection with a built-in screen protector. However, as I have been using my iPhone, I have experienced some of the battery issues that have been reported since it was released. When I am in the office or at home, it is easy to keep the battery fully charged. When I am on the road, however, this isn’t always the case. To overcome this, I swapped my Otterbox for the mophie juice pack plus, which was given to me by the company. The case combines the protection of a hard shell case with a built-in battery that more than doubles the life of my iPhone 4S.

Out of the Box

The juice pack plus comes in two pieces. You slide your iPhone into the larger piece and plug it into the standard iPod/iPhone port at the bottom. Once you have done that, the second piece slides onto the top of your phone and locks with the lower section. While the sliding mechanism is smooth and easy, the locking mechanism is strong enough to hold the two parts together, even while removing the phone from a bag or your pants pocket.

The case itself is a dual-injected hard shell with a protective shock-proof rubberized band. While it doesn’t give me quite the same sense of security I get with the Otterbox, I feel that my iPhone is well protected. I am partial to built-in screen protection, which the juice pack plus does not offer. However, you can buy screen protection film that will also do the job.

Undoubtedly the biggest complaint I hear about the juice pack plus is the bulk it adds to the iPhone. The case measures 5.10 inches by 2.57 inches by 0.71 inches and weighs 2.5 ounces. Adding this to your iPhone almost doubles its thickness, yet it still fits in a pants pocket. If you already use a case, you probably won’t notice the added weight too much. Personally, I think the added weight is a worthwhile trade-off for longer battery life.

On the left side of the case are dedicated volume up/down buttons, so making volume adjustments is very easy. Accessing the recessed mute/ringer button above the volume buttons is a little tricky, but it also makes it unlikely that you will accidentally mute or turn on the ringer at an inopportune time. At the bottom left of the case is a power toggle switch, which allows you to decide when the phone is drawing power from the juice pack battery. There is also a micro-USB port at the bottom right of the case for simultaneous syncing and charging. On the bottom of the case is a battery status button that, when depressed, lights up to four LEDs to show the charge level of the juice pack (they also light up when charging). Lastly, on the top of the case you will find a dedicated power button as well as a cutout for the headphone jack.


Mophie claims that the juice pack plus is capable of upping your talk time by up to eight hours on a 3G network or 16 hours on a 2G network. Alternatively, the battery case will give you an extra seven hours of 3G browsing time or 11 hours of Wi-Fi browsing time. Based on Apple’s estimates for the iPhone’s own battery, the juice pack plus may more than double your usage.

You can use the juice pack plus in one of two ways: You can turn the case off and use the iPhone’s own battery until it is close to running out and then turn on the juice pack plus to charge the iPhone’s battery, or you can use the juice pack plus first, preserving the iPhone’s battery until the juice pack runs out.


Being a fan of hard cases for my iPhone, I like the construction of the mophie juice pack plus. The added bulk gives me a sense that the case will be able to withstand most of the bumps and jolts I subject my iPhone to over the course of the day. While it more than doubles the thickness of my iPhone, I didn’t find the added mass unwieldy. My only wish was that there was a built-in screen protector, but that is just my own paranoia.

Knowing I am less likely to be stuck scrambling for a charger is the real bonus of the juice pack plus. Being able to double your battery life isn’t something to overlook, especially when traveling.

At $100 (less if you shop at, the mophie juice pack plus isn’t cheap. But when you consider the level of protection and the added battery life, I think it’s a worthwhile investment for anyone with an iPhone 4 or 4S.


  • Long battery life (perhaps as much as double that of the iPhone 4/S battery)
  • Sturdy construction
  • Battery indicator lights


  • Doubles thickness of iPhone

mophie juice pack plus—iPhone 4 & 4S Battery Case

$99.95 (currently $56.99 from


Wayne A. Thorp, CFA, is the author of “Gadget Corner.” All reviews are based on firsthand experience of the product or service. No third-party compensation is received for opinions on products, services, websites or topics. However, sometimes the author is not required by the manufacturer or their PR firm to return the product under review. In such instances, it is our policy to convey this within the review. The views and opinions expressed in these reviews are strictly those of the author. Any product claim, statistic, quote or other representation about a product or service should be verified with the manufacturer or provider.

Wayne A. Thorp, CFA is a vice president and senior financial analyst at AAII and editor of Computerized Investing. Follow him on Twitter at @WayneTAAII.


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