iPhone Case Review: Third Rail System Battery Case for iPhone 4/4S Reviewed by Tom Slayton
Editor's Ratings (1-5): 4.5
What's Hot: Slim case for everyday use with a battery that firmly attaches in seconds. Battery also allows you to charge other peripherals with the included cable.
What's Not: 1250 mAh LiPo battery is a bit small compared to other battery cases, and doesn't quite double the capacity of your iPhone's 1450 mAh battery.
The Third Rail System for iPhone 4/4S is a battery case with a twist. Instead of building the battery into the case, the Third Rail allows you to quickly and securely attach the battery to the back of the case only when you need it. The inclusion of an output jack also makes it possible for you to charge other USB peripherals via the included adaptor cable.
Size and Fit
The unencumbered Third Rail System case is slim, and adds almost no width or depth to your iPhone, although, it does make it longer to accommodate the necessary dock connector. This is a unique design that allows you to keep the battery in your purse/pocket/briefcase, etc until you need it. Since the extra battery is by far the heaviest part of any battery case, this means your iPhone won't feel like a doorstop like it does with most other battery cases.
Features and Quality
The folks at Third Rail have obviously put a lot of time and effort into designing a battery case that is as light as possible. The naked case is constructed of sturdy ABS plastic, and has a pleasant soft-touch feel. The 1200 mAh battery attaches in seconds, and requires no cables or connectors. Just slide it onto the rails on the back of the case and you're off and running. You can also stack batteries (sold separately), which is particularly useful for charging. But wait, there's more! You can also charge USB peripherals from the battery via the included adaptor; a nice touch, to be sure, for any of you with Bluetooth headsets or even a second phone.
This brings me to my only real gripe about the case. The measly 1250 mAh battery capacity means you will probably be coming up short if you try to charge a completely dead iPhone 4 (1450 mAh capacity) or more than one device. Personally, I would gladly carry around a little more weight in exchange for a larger capacity. I suppose I can do that, however, if I'm willing to pony up for an additional battery. All-in-all, it's the most elegant, feature-rich battery case I've ever used.
The Third Rail case falls clearly into the minimalist camp as far as style goes. It's black, slender, and doesn't come with any sequins, rhinestones, or hood ornaments. This is ideal, as it means the case (with or without battery attached) will be equally at home in a college dorm or a boardroom.
The Third Rail Battery Case for iPhone 4 stands out from the crowd due to its innovative sidecar design. The ability to securely attach a battery only when you need it means you won't feel like you're holding a doorstop up to your ear 90% of the time. The battery capacity is a bit on the low side, but this also means that the case, even with a battery attached, is surprisingly slim and svelte. Lastly, the ability to charge USB compatible peripherals and stack additional batteries for charging really adds to its usefulness. Highly recommended.
Slim Case: 4.96 x 2.43 x 0.46 inches; 0.85 oz Smart Battery: 3.29 x 1.83 x 0.27 inches; 1.4 oz Battery Capacity: 1250 mAh lithium-ion polymer battery Package Contents: Slim Case for iPhone 4, Smart Battery, Micro-USB Cable, USB Adapter, User's Manual Case Compatibility: Works with every iPhone 4