Quote Originally Posted by Gameguy View Post
USB is a standard, it should be 5V and 500mA.
5V is a USB standard. 500mA was the minimum until it changed to 900mA with USB 3.0.

That being said, there are many devices that require more power to charge or even operate, like a Pi3 which will give errors (lightning bolt symbol) if you're using a power supply under 1.5A. I'd be surprised if the packaging for the TG/CG mini doesn't state the minimum power requirements.