Third Rail Mobility has unveiled its new modular Battery Case system for the iPhone 4. Unlike traditional battery cases, which feature integrated, non-removable batteries, Third Rail’s solution combines a slim case with a detachable 1250 mAh lithium ion battery pack, allowing users to remove the battery when it isn’t needed, or swap a depleted battery out for a charged cell for extended use. In addition to charging the iPhone, the batteries can also be used to charge other devices via a micro USB adapter; the case itself offers full access to all ports, controls, and cameras, save for the Dock Connector. Third Rail Mobility’s new Battery Case system for the iPhone 4 is available now and sells for $90; the slim case is available separately for $40, while additional batteries sell for $60 each.
Charles Starrett was a senior editor at iLounge. He's been covering the iPod, iPhone, and iPad since their inception. He has written numerous articles and reviews, and his work has been featured in multiple publications.