The $80 Juice Pack Helium has a 1500mAh battery, and the $100 Juice Pack Air has a 1700mAh battery.
The mophie juice pack plus is made for the user who puts their iPhone 5 through the paces morning to night, maxing out features, apps, video, email and web browsing while on-the-go. The case features a 2100mAh battery, translating to an added 120 percent of extra battery life and offers the most power of mophie’s battery case solutions for the iPhone 5 to date. For protection, the juice pack plus’ dual-injected sleeve is engineered with a shockproof band and anti scratch guides to help buffer the impact of falls.Like the other cases, the Juice Pack Plus uses a microUSB cable to charge.
The Mophie Juice Pack Plus is available for $120 in black, white and PRODUCT (RED) from Mophie's website and elsewhere.