I think it's a pretty safe to assume that many iPhone users have found themselves in a precarious situation of being out and about somewhere miles away from home - or any usable power source - only to answer a phone call or send that all-important text message and watch their phone power down as the battery sinks past that horrible 1% mark. It's a horrible but an oh-so-familiar feeling, and unfortunately one that comes as part and parcel of owning a portable but power hungry device like the iPhone.