British designers iKit have added the NuCharge battery case to their line of iPhone 4 accessories. The product acts as both a lightweight spare battery and a protective case, and is compatible with both the AT&T and Verizon iPhone 4s. The black (also available in white) case is only six millimeters (0.24 inches) thick and adds only two ounces to the weight of the iPhone 4, but doubles the battery life by sporting a full 1400mAh battery.
