This portable battery charger is the second device in my possession and also a great helper as the first, because one thing first: It fills in the "emergency" exactly its purpose. I was also amazed at how fast my iPhone was recharged. Unfortunately, and therefore the deduction of points, there are two little things that I have learned more comfortable. First, the charging of the charger itself takes quite long, but if you think something foresight, is not a real problem. The second is that I could not charge my iPhone than once from 0 to 100. I personally find not so bad, but when you're used to having more goes, you miss it suddenly.