iPhone 4/4S Battery Cases Compared

The iPhone 4 wasn't the success it was because of great battery life. When the 4S came along this problem got far worse. Yet Apple still seems to be able to sell all they can make.

All those iPhone users need help, and the most convenient solution may be to buy a case for the phone that integrates an extra battery. The iPhone plugs into the case and acts, while the case's battery has charge, like it is plugged into a wall socket. We looked at 9 such cases and here are the results.

The 9 we did test were (alphabetically): Boost Case, Boost Case Plus, Boost Case Leather Flip Case, Incase Snap Battery Case, Incipio OffGrid, Mophie JuicePack Air, Mophie JuicePack Plus, RichardSolo Power Case and uNu Power DX-1700. It's a crowded market; several other vendors either didn't respond to us or declined to participate.

Some cases we tested were sleeker than others, some give a choice of color. Three of the cases were essentially identical. The cases ranged in price from $50 to $99, but in many cases they are available for less than these list prices. We bought one case for $35 on Amazon.com, but this was well below the list price.

We did not do formal battery life testing. A fair test would require laboratory conditions to control signal strengths and other such esoteric matters. The best proxy available for measuring it is the battery capacity, which vendors provide generally as "mAh" or milliampere-hours. The median capacity in this group of batteries was 1700 mAh and the average a bit over 1600. There is more to the consideration than capacity. For example, all of these cases have circuitry for charging and draining the battery and it is possible for quality differences to affect performance.

Late in the process we took all 9 cases and examined them live. Here's the video of how that went:

Alternatively you can watch the iPhone battery case comparison video on the BYTE TV page.

Which case is the one for you? This is, of course, a personal decision. The testers came up with a few points to consider:

• Of the 3 identical cases, there's no reason to buy anything but the cheapest. In our research it was the uNu, but we recently found another for even less. You'll need to do a little shopping.
• Only one, the Incase, exposes an Apple 30-pin connector externally. The others all expose a microUSB connector. If you have peripherals which use this connector, as many car docks, exercise equipment and clock radios do, the Incase may be your best choice.
• The only reason to get one of these cases is to extend battery life, but some users will still have greater needs than others. If you just need a little more oomph to get through the day you may not need the biggest battery, and therefore can get away with more of a style decision, and some of these cases are clearly better looking than others..
• It's hard to tell whether you really like one of these until you get it in your hands with a phone in it. Is it too heavy? Does it fit comfortably in your pocket or wherever else you would want to store it? Make sure to consider the return policy wherever you buy your case. Our 3 testers preferred 3 different cases owing to 3 different sets of personal priorities.

Click below for the individual reviews:

	Boost Case Leather Flip Case		Boost Case Plus
	Boost Case/RichardSolo Power Case/uNu Power DX-1700 (Eix)		Incase Snap Battery Case
	Incipio OffGrid		Mophie JuicePack Air & Plus

Ben Gottesman and Fritz Nelson contributed to this review. Ben has been reviewing technology services and products and consumer perceptions for over twenty years. Fritz is the editorial director for InformationWeek and the Executive Producer of TechWebTV. Fritz writes about startups and established companies alike, but likes to exploit multiple forms of media into his writing.

Larry Seltzer is editorial director for BYTE.