iBattz’s Mojo line of lithium-ion battery-equipped iPhone 4/4S cases have a trick up their sleeve should you manage to use up both the phone and the case’s batteries – the battery in the case can be swapped for another.
The Mojo is available in three versions – the Vogue, the Armor and the Classic.
The most basic of the three, the Classic offers protection against “knocks, drops and vibrations.” Its built-in 1500mAh rechargeable battery is claimed to double the battery capacity of the user’s iPhone. That battery takes 3.5 hours to charge, and should be good for 500 charging cycles.
The Classic also takes standard BP-4L battery modules, so if you want to buy a spare or replace the one it came with, you should be able to find one relatively easily. The case weighs 75 grams (with battery), and is available in black or white for US$49.90.
Next up is the Vogue, pictured at the top of the page. It shares the Classic’s key features, although it has a 1700mAh battery, a battery charge indicator, and comes with a second battery included. It’s available in 12 color combinations (thanks to interchangeable back plates and bumpers), and sells for $89.90.
Finally, there's the Armor. It features an exoskeleton design and silicone-sealed ports, to offer additional protection against shocks, splashes and dust. This case is a little heftier than the other two, weighing in at 120 grams with battery.
It’s available in grey and black (again, with interchangeable back plates and bumpers of other colors) for $99.90.