Charging time depends on various factors such as input source and cables. The product will charge any USB chargeable device (including phones) at the maximum speed that the device’s manufacturer has allowed for in the device configuration.
For those power banks with a power button, you must press the power button first to turn on the power bank. There are a few AUKEY power banks that do not have a power button that will begin charging as soon as it is plugged into the device.
Capacity is measured in milliamperes (mAh) on power banks. As a general rule, the more mAh in the power bank, the more times you will be able to charge your device before having to charge the power bank again.