one
Connect your phone to a cable and a charging head to charge it.
two
After plugging in and charging, the phone immediately sounds the charging prompt tone and lights up the screen, which is slow charging, and if there is a delay, it is fast charging.
three
Check the logo on the charging head to further verify whether it is fast or slow charging.
When charging, if the phone rings \"ding\" twice in a row, it means that your iPhone is undergoing fast charging.