I have in no way viewed a person get concern with the conditions amperage/wattage (While admittedly I am unsure how frequently they appear up), nor do I get difficulty myself. I am also an electrical engineer. About the flipside, if all you need to do is charge your iPhone, then https://usbchargerblock12097.daneblogger.com/26387168/considerations-to-know-about-usb-charging-block