Since so many products we receive for review have been designed by one company and then modestly tweaked or rebranded for another, it’s not unusual these days to see two cases with different names and nearly identical designs. Still, the situation with Incipio’s offGRID ($70) and iKit’s NuCharge ($65) battery cases for the iPhone 4 is pretty strange. At first glance, the cases look almost identical, right down to specific curves both inside and out; each does have legitimate cosmetic differences, but they’re small. Yet we were genuinely surprised by the performance distinctions between the cases, one of which is advertised as having higher battery capacity than the other, but winds up delivering less of a boost to the iPhone 4.
The basic case design is quite similar between offGRID and NuCharge. Both are black plastic sleds, offGRID glossy- and NuCharge matte-finished, designed to be as small as can be by battery case standards—they’re noticeably shorter and thinner than most of their rivals. Your iPhone 4 slides in between two plastic side walls and a Dock Connector plug fits into the port on the bottom of the device. All of the back, except for the camera and flash, is covered. The left side has an opening for the ringer switch and volume buttons, large enough to accommodate the differences between GSM and CDMA devices.
Both cases have removable top caps that match the rest of the body, with very small cutouts for the headphone port, noise-canceling mic, and Sleep/Wake button. The NuCharge headphone port hole is almost ridiculously small, though you can pull either case’s top cap off if you need full port access.
On the front of each case, underneath the iPhone 4’s bottom edge, is a glossy black strip that runs all the way across. While the whole thing is flat, the left side can be pressed to both turn the case on or off and to display the current battery life across 4 LEDs. While iKit’s is solid all the way across, Incipio’s has two thin holes at the top: one for the speaker and one for the microphone. Call quality was just a tiny bit better on the latter model, but it was only slightly noticeable. Along the bottom edge of both cases there’s a Micro USB port for charging and a grated opening over the microphone on the left side.
One of the big differences between the two cases is the finish. As noted above, iKit chose to use a soft-touch, matte plastic while Incipio went with glossy, a difference that will have long-term consequences. Soft-touch coated accessories tend to peel after a period of extended use in a pocket or bag, while glossy accessories develop a patina of scratches starting early in their lives, but don’t peel.
Other minor changes: NuCharge’s sides are flat, while those on offGRID are rounded. NuCharge also has a metal strip that serves as an accent, and a built-in stand located right next to the camera, sitting flush against the body of the case when not in use and folding out when needed. The case stands on a recline in both landscape orientation and upside-down portrait orientation. This second position actually works very well for FaceTime calling, but not much else.
The battery inside of Incipio’s case has a capacity of 1450mAh while iKit’s holds 1400mAh. We naturally expected the former to provide at least a little more of a charge than the latter. In our testing though, the opposite was true. For both cases, we tested a powered-on, 3G/Wi-Fi-connected iPhone 4 with the screen turned off, no calls coming in, and no audio playing.