The battery life of a phone has always been the subject of consternation for those who use them unsparingly - be it for web surfing, gaming and checking your social media apps. It doesn't help that the iPhone's library of apps is astoundingly huge, allowing users to guzzle its battery life into oblivion by the end of a day. Well, thankfully, there's the MiLi Power Spring 4, an external battery pack built specifically for the spanking new Apple iPhone 4.
What exactly is the MiLi Power Spring 4? This contraption acts not only as an extended portable charger, but also a protective casing. Those more concerned with aesthetics may not like the Power Spring 4 - it is not exactly a head-turner in the looks department. Case in point: we had on hand, a black version that came in a plain and unattractive plastic exterior, albeit being grease and fingerprint friendly. It was also sturdy and scratch-resistant; throwing it into a bag with other belongings yielded no scratches or cracks.
The other thing you will notice about the product is that while it is relatively light at 74g and thin at 124 x 65 x 18mm, it adds a considerable girth to the slim iPhone 4; i.e., the weight of both combined goes to almost 200g with an average of about 6mm added to all three dimensions of the phone. Of course, the trade-off is that you will get an extra 1600mAh worth of battery juice - significant not only because the Apple iPhone 4, like its predecessor, comes with an irremovable battery but because it offers above average mileage compared to other phones with 1300 - 1400 mAh batteries.
Using the battery pack is extremely simple - slide the iPhone 4 in from the top, and clasp it tightly after it is in position. There is a LED indicator bar on the bottom right that tells you how much battery life has been depleted, and it is positioned alongside a button that allows you to switch it on or off. When the Power Spring 4 has been totally depleted, simply plug in the USB cable to charge.
We noted that the battery pack does what it sets out to do, clocking in at an extra 6.5 hrs of battery life with 3G switched on and intermittent web surfing and calls.
At a reasonable $99, the MiLi Power Spring 4 is a useful addition to your everyday tech gear, that is, if you are not too troubled by its unassuming exterior. Doubling up as both an effective portable battery pack and a protective cover, it is likely to attract consumers with its practical bent and dual purpose.