If you want to buy a charger for your smart watch, bluetooth earbuds/headphones, etc because they only came with a USB cable and it's not convenient to have them charging in your computer, etc., here's what you need to know to buy a charger:
They are measured in Volts and Amps.
USB ports 1.x, 2.0 - black plastic have a standard power output of 5V 500mA (or 5V 0.5A).
USB ports 3.0 - Blue plastic have an output of 5V 1A.
Fast charging ports vary, they can be 5V/9V/12V and have 3A/5A/9A. The lowest for fast charging is 5V 3A.
If your USB cable has a Black plastic, you need to match the charger to USB port 1.x/2.0; if it has a blue plastic, match it to USB 3.0 (charger will also have a blue plastic).
For Fast charging cables (any other color generally green or purple), unless the manual or the box says how many volts and Amps the device needs, buy a 5V 3A charger. You can always go down on V/A, you can even use a 5V 1A charger (equivalent to USB 2.0) on a fast charging device, but you can't go up. if your device uses 5V 3A, trying to charge it with 12V 9A might damage your device.
The way you know if the charger has the correct output is by looking in the box or the charger itself: on the small letters of a charger, it says the output, among other information.
They are measured in Volts and Amps.
USB ports 1.x, 2.0 - black plastic have a standard power output of 5V 500mA (or 5V 0.5A).
USB ports 3.0 - Blue plastic have an output of 5V 1A.
Fast charging ports vary, they can be 5V/9V/12V and have 3A/5A/9A. The lowest for fast charging is 5V 3A.
If your USB cable has a Black plastic, you need to match the charger to USB port 1.x/2.0; if it has a blue plastic, match it to USB 3.0 (charger will also have a blue plastic).
For Fast charging cables (any other color generally green or purple), unless the manual or the box says how many volts and Amps the device needs, buy a 5V 3A charger. You can always go down on V/A, you can even use a 5V 1A charger (equivalent to USB 2.0) on a fast charging device, but you can't go up. if your device uses 5V 3A, trying to charge it with 12V 9A might damage your device.
The way you know if the charger has the correct output is by looking in the box or the charger itself: on the small letters of a charger, it says the output, among other information.