I'm starting school at Berkeley this fall. I have iPhone 4 which I use A LOT in college. However, it's impossible to charge my iPhone on campus. So I bought this portable battery. Then my phone last all day long!!! From 8:00am to 7:00pm, still have 60%. And the iTorch? I just use it to charge my phone for 30mins. It stills shows a full battery. I charge this iTorch once a week or every two weeks. It really holds a lot of juice.