Since the battery of my iPhone 4 for longer trains unfortunately never enough I was looking for a portable USB charger. Criteria for this were: should fit in my handbag, the quality should agree and it should be at least enough for a full battery charge.. By Compad Power Bank 3000 I have a mobile USB charger found exactly that meets my criteria. As a convenient feature provides the Power Bank 3000 even a 3-in 1 cable, so that even friends with other phones to use them in an emergency. Also I noticed that the Power Bank 3000 faster than ordinary loads loader equipment.