The item does what it's supposed to, but for some reason my phone (HTC Hero) takes a few moments to realize it is plugged in when plugging into this adaptor; It usually just lights the moment its plugged in with any other usb device or charger. Maybe the voltage is low, or there's less current available than it should, I don't know; but it does charge the phone when it is plugged in. I don't usually have 2 devices plugged in at once, I just wanted the extra plug in case I needed it. In my 2nd car, we keep a gps plugged into the other one and it works fine.
Compatible With:HTC One M8/ One M7/BlackberryZ10.Use your car to charge any devices (digital cameras, PDAs, mobile phones, USB accessories and more) that can rely on USB for power! This adapter plugs into your car's cigarette lighter jack to become a powered USB port. Apple® iPod®, iPhone®, or iPad® are registered trademarks of Apple, Inc. Products are Apple® compatible and not endorsed by Apple, Inc.