Review: MiLi Power Spring 5 for iPhone 5
It took longer than expected for iPhone 5 battery cases to make it to market, and the earliest ones worked around Apple's tight restrictions by using removable Lightning connectors that tucked into the batteries' bottoms when not in use. As of now, traditional battery cases -- those with fixed connectors in their bases -- are rapidly becoming more available, but some tuck-in batteries continue to hit stores, most recently including MiLi's Power Spring 5 for iPhone 5 ($70). This shell-style case packs a 2200mAh cell, and is relatively compact compared to many of the battery cases we've covered.
Unlike most battery cases, Power Spring 5 is only as tall as the iPhone 5 itself. The plastic has a very nice finish comparable to Juice Pack cases we’ve seen from Mophie; although it is available in black and white, our review unit came in a blue-tinted grey and felt quite nice. At less than 0.6” thick, it’s the same thickness as Juice Pack Helium, yet boasts almost 50% greater power capacity. Unfortunately, the design of the case itself is lacking. As a shell, it covers the iPhone’s tall sides edges, but leaves both the bottom and top completely exposed. Were there not a battery inside, we’d likely not even have reviewed it, as we generally recommend cases that offer more thorough protection.
Like most battery cases, this one incorporates a Micro-USB port for recharging with the included cable, and an array of battery indicator lights, which are triggered by pressing the lone button on the back. There’s no dedicated power on/off control. When it comes time to charge, the rubber-coated Lightning connector that runs along the bottom edge easily pulls out, and the plug fits into the phone’s center bottom port.
We tested Power Spring 5 the same way we test every battery case: an iPhone 5, connected to Wi-Fi and the cellular network, was fully drained before being connected. We let the battery run for as long as it can, and found that it was able to provide a 104% charge. That’s higher than the average for 2200mAh cells, and certainly more than we expected.
Despite the fact that we don’t love the body of this case, or the fact that there’s not a fixed connector, it’s hard to deny Power Spring 5’s impressive combination of performance and price. No other proper battery case—in fact, no other battery solution made to work specifically with the iPhone 5—packs that kind of a punch. If you’re more concerned about budget and power than overall protection, this is an option worth considering. Mili notes that it’ll cost even less if you buy it from Amazon, although we’d advise some caution, because the company seems to have a number of sites, and some actually charge more than $70. On its merits, Power Spring 5 earns our strong general recommendation.