Ohh fantastic case for iPhone 4 , when you get your case, you’ll use it and once your iPhone hits a low battery, you can use the hidden rechargeable smart battery by flipping the switch on the bottom left of the case and the iPhone will begin to charge instantly.
Mophie Juice Pack Air case also keeps your iPhone’s quality of materials as it really protects unlike some other cases which hurts youriPhone material.
Usually user have their Mophie on the phone and once it hits about 20-30% battery life they simply flip the switch on the bottom left of the case and the iPhone begins to charge instantly. The case has enough battery power to get the phone back to the 80-100% charge range, depending on where you are starting from. This is rather cool and who hasn’t tried running low at times where the phone is really needed but there are hours until a regular charging is possible. Another great use case is for iPhone owners where the battery is getting old and where it can’t charge to a sufficient level any more. The Mophie Juice Pack Air Case can really help you in this case.