I am looking to buy and external battery from Amazon because I have a few gift cards to Amazon. I was considering an actual battery case but most of those only recharge the phone once which in most occasions would be fine. However, the main reason for this would be to charge my phone and maybe iPad for long periods away from a power outlet. I am looking for something that can charge a phones at least 3-5 times per charge. I am also looking for one that isn't extremely bulky. One that can fit in my pocket and not feel large. What are your recommendations from what you have seen or experienced yourself? Thanks!