Normally the voltage of QC 2.0 power bank is 5V 9V 12V 20V.
But it is more elastic for QC 3.0 power bank. Its voltage range is from 3.6V to 20V.
So it has much more elasticity to match different smart phones and provide the best voltage and current.
Output: 5-6v 3A, 6-9V 2A, 9V-12V 1.5A