Incipio OffGrid Pro offers a unique take on iPhone battery cases

Incipio’s $100 OffGrid Pro Backup Battery Case offers a unique take on the iPhone 4 and 4S battery case. The removable, 1700 milliamp-hour battery sits in a recessed space in the inside back of the case, and the package includes a second battery that you can charge separately with an included slim charger—you can swap the batteries as needed.

Battery aside, the OffGrid Pro case itself consists of two pieces: the main case—which is essentially the back of the case and the dock-connector area at the bottom—and a wraparound bumper. Together, they form an exceedingly tight fit around your iPhone. Sliding your iPhone into the main case is easy, and snapping the bumper around the setup doesn’t take much effort, either. Removing the case, on the other hand, requires considerably more effort than I’d prefer: A tiny notch at the bottom of the case offers a sliver of room for your fingernail to pry off the bumper.

On the bottom-front edge of the case sit four blue LEDs that show the battery’s power level. Just to the right of those lights is a tiny power button you push for two seconds to toggle phone charging on and off.

The OffGrid Pro is impressively svelte, measuring just over 5 inches long, 2.4 inches wide, and 0.6 inches thick; it weighs just 2.5 ounces. That makes it ever-so-slightly shorter, narrower, and thinner than Mophie’s Juice Pack Plus( ).

The case covers the volume and Sleep/Wake buttons with press-through overlays of its own that work fine. The case provides a cutout around the Ring/Silent switch, and the OffGrid Pro is slim enough that accessing that switch doesn’t require extreme finger gymnastics. There’s also a cutout for the iPhone’s headphone jack, but it’s small enough that many third-party headphones won’t be able to successfully plug in. For example, the plug on my beloved Shure SRH440 headphones can’t fit into the jack unless I use a third-party adapter.

The case doesn’t offer any kind of screen covering, and its sides sit flush with the iPhone’s screen—they don’t extend beyond it—so they won’t protect the screen when you set the iPhone (or it falls) face-down.

On the bottom edge of the case, on the right, is a cutout for the iPhone’s bottom speaker. Where a similar cutout would be on the left-hand side instead sits a Micro USB port for syncing and charging your iPhone and charging the OffGrid Pro’s battery. That design means your iPhone may sound a bit quieter in the OffGrid Pro, though the difference isn’t especially noticeable.

Overall, I like the OffGrid Pro. Each of its two batteries should be able to double your iPhone’s charge, and the battery is slim enough that bringing the second along won’t take much room in your pocket or bag. The case adds minimal thickness and weight to your iPhone given the power it provides. The downsides? The case’s polycarbonate surface feels a bit slippery in my hand, and the case affords zero screen protection. But if it’s power, not protection, you crave, the OffGrid Pro is a solid option.