The Mophie Iphone 6 Juice Pack Plus can provide 120% extra battery life.
Aside from providing extra battery life the Mophie Juice Pack Plus also provides protection from scratches and falls. The bumpers on around the case actually has rubber support pads to give your phone added protection against drops. When charging the case it makes sure that the phone is charged first and then it charges the case. When you need to charge your phone you simply flip the little switch to allow the Mophie case to charge your phone. The battery in the case is a 3300mAh rechargeable. The case weighs 3.9 oz so you don't have to worry about it adding needless weight to your phone.