This article first appeared in HWM June 2012.
When it comes to iPhone cases, the Third Rail Slim case bucks the trend of superfluous aesthetics and no substance. Stylish with its understated matte-black finish, the top third of the case breaks apart to allow insertion of the iPhone. Though it adds a few extra centimeters to the lengths of the Apple device, it encapsulates the iPhone well while still providing access to all the buttons.
As the name suggests, a key feature is the slide-on battery which slots in at the back of the case. The battery itself has a set of five lights which indicate the level of charge for the device. A micro-USB port allows you to plug the battery pack up to a power source. Similarly, a proprietary second port and USB adapter cable lets you charge devices besides your iPhone. While the case blocks access to the 30 pin iPhone connector, you can still sync your smartphone using the micro-USB port.
The battery itself features lithium ion polymer technology and provides 1250mAh of capacity. When tested, this was enough to supply two thirds of the iPhone’s maximum power capacity, adding about four extra hours of usage for the device. A total of six battery packs can be stacked on top of each other for even more juice while on the go.
Priced at S$159, the Third Rail system is easily one of the more flexible battery packs for the iPhone today, with a multi-stacking, hot-swappable battery that gives it a unique edge against the competition.