Note: Third Rail Mobility sent me a copy of their product for review.

iPhone road-warriors have several power options: They can moderate their usage (yeah, right), carry a charger, or tote a back-up battery system. Third Rail Mobility has an elegant product that, while limited in application, serves as a great back-up power source.

Since the vast majority of Apple devotees are attached at the hip to their smartphone toys, option #1 is moot. And power adapters are useless without a handy wall outlet. The most versatile option is some sort of wireless charging system, though not all gimmicks (er, options) are created equal.

I’ve tried them all: kitschy solar-power solutions, magnetic induction systems (i.e. Powermat), and battery attachments. Some of these items (or tech demos, in some cases) work better than others. Third Rail Mobility’s solution is worth checking out.

The eponymous Third Rail system includes a special case, a “smart battery,” and cables for wall or USB charging. The smart battery attaches to the back of the case and provides a boost when the phone runs out of juice. In theory, this sounds great, and I have no complaints with the tech – when I needed the device, it was a life-saver.

But that’s just it – I couldn’t find much practical use for it. My personal situation could be different from yours. 90% of the time, I’m either at work (with wall outlets and USB ports available), at home (same), or doing some activity (say, running) that precludes mobile-phone usage. I just travelled to Boston via Amtrak, which includes wall outlets at each seat.

I might be a degenerate techie, but I have back-up power solutions at each “port of call.” So the Third Rail system is useful only in situations where I’m completely off-the-grid. I don’t take regular public transit, go camping, or do long road trips (where I’m not the driver). The Third Rail would be a godsend on cross-country jet rides (or should I ever decide to become closer with nature).

Their website recommends “multiple batteries” to swap out for “longer periods away from outlets.” But, notwithstanding an international trip, I can’t possibly imagine being untethered for that long. The iPhone’s battery is notoriously skimpy, but it usually lasts through a day of moderate usage – even a day spent away from an outlet.

If your routine mirrors mine, then the Third Rail system may be a tad superfluous. But if you take public transit over long, daily commutes, you fly a lot, or you like to be outdoors (for some inexplicable reason), then the Third Rail is an excellent back-up power system. And who are we kidding? Most geeks drool over redundant functionality.

The Third Rail system is available for $89.99 at