MiLi's Power Spring 5 ($80) for iPhone 5 is the latest battery case to feature a Lightning connector; like some of the early models we've seen, this one doesn't have a fixed Lightning plug, but rather a removable one that tucks into the back when not in use. A 2200mAh battery is inside, which should be enough for a full iPhone 5 recharge; we'll confirm this during real-world testing. The case itself is a shell, meaning the top and bottom edges are…
