Australian Review: Mophie Juice Pack Air for iPhone 6 – Amped
The Juice Pack Air has a 2750mAh battery hidden away inside of it, enough to fully recharge an iPhone 6 from flat to full. Charge times are similar to what you'd expect when charging from a power outlet – I was able to get an extra 15% of battery in about 15 minutes, and completely recharge my iPhone 6 in two hours.
The case itself recharges over microUSB and takes a little over two hours when plugged into a power outlet. If you're charging the case with your iPhone 6 sitting in in it, the Juice Pack Air will recharge your iPhone 6 before replenishing its own supply. You're also able to sync your iPhone 6 without removing the case.