Answer by KC Yee:
the usb cable and connector are the same, but the chargers are different.
So with a different brand charger, it may only able to slow charge your phone, while a compatible charger will be able do a quick charge.
The difference is caused by the battery feedback signal to the charger. if the signal is not compatible or understood by the charger, the charger will default to the safe slow charging mode.
Fast quick charge without battery feedback may result in over charging and over heating of battery, and also reduces battery life cycle. K C Yee