Graver clothing has a new selection of power banks for your devices that are great to power your devices on the go. Mobile phones/ ipad and Tablets /mp3 players. They are PERFECT FOR CATCHING POKÉMON ON THE GO. handy hint your phone battery is on average 2400 mah. We have all different sizes of power banks from 2400mah to 100 000 mah depending on size is how many times it will charge you device.