The Anker 621 Magnetic Battery (MagGo) 5000mAh has been launched in the US on Amazon. The gadget has been designed for the latest iPhone models, with a maximum power output of 7.5 W. MiniCell technology keeps the portable device compact at 0.45-in (~11 mm) thick and weighing 5 oz (~142 g), with strong magnets to hold your phone in place.