Third Rail Mobility introduces its Third Rail System battery case for smartphones that includes the Slim power-ready protective case and Smart Battery universal, interchangeable, removable battery. Unlike other smartphone battery cases, Third Rail’s system provides several different usage modes in one simple system – functioning as a protective case, a power case, a portable external charger and a power hub for charging multiple devices at one time.


The Third Rail System will be initailly available for the iPhone 4. The Slim Case is the thinnest battery-enabled case on the market, while the Smart Battery is a super-slim, 1.4-ounce rechargeable 1250 mAh lithium­ion battery. Unlike other battery cases with built-in battery, the Smart Battery slides onto the Slim Case for an easy charge and can be removed when power is not needed, leaving users a sleek, slim protective case.


The Third Rail System battery case is priced at $89.99 while individual components are sold separately: $39.99 for the iPhone 4 Slim Case and $59.99 for an additional Smart Battery.