Verified Purchase(What is this?)
This review is from: New Trent (2PCS) Combo-Pack: Dual High-Speed USB Port Car Chargers w/ Free Full Speed Micro-USB Charging Cable - 1pc 15W black and 1pc 15W white (NT89T) (Electronics)
I bought this because my Car Audio USB couldn't charge my phone while using it, and thought that at least the 2.1A exit would do the job, but no.
I don't know if it my Samsung Galaxy S3 or the charger output, but the same thing happens - the phone looses charge while in use and connected to the charger.
At home, with just a 1000mA charger, I can use and charge the phone at the same time.
In the car, using either the 1000mA or the 2100mA outputs, the phone still looses charge.
The phone does say it's charging and since I've no direct way of testing the output of the charger, can't really say it doesn't work.
I guess for charging, while the screen is off, it's ok.
Love the low profile form and that includes microUSB cable.