Here help the fast, affordable and effective 2-port USB solution RAV-power, which, though detected the origin of "China-gadget" arises, but this is a good, constant and practicable charging adapters. For this purpose, the equipment for an article in the low-budget range even almost above average, because in addition to a quite conventional LED status indicator protects the dual adapter from overheating and overcharging, offers by the slightly larger (screw-on and in an emergency on its own to be repaired) plastic case sufficient distance between the two USB inputs and effortlessly invites two supposedly strong power-hungry at the same time.
To date, the Mini Charger, despite a considerable number of experimental devices with a USB port not once refused to serve and even supplies this half-eaten apples, so does not seem to be picky in reverse.
Or to put it in the advertising slogan of a famous electric market short and painless to the point: "So has technology".