Just like a charger plugged into a wall.
However, in order to charge your devices on the go, your power bank itself has to be charged.
Plug the larger end of the USB cord into the wall adapter.
This will increase it's battery life.
Arge your electronic device and power bank simultaneously.
2# Letting the Power Bank Charge.
This video shows How to make powerbank at home DIY.For example, if your phone is 2600 mph, and your powerbank is 10000 mph, you can charge about 3 times.Such as Tattu 2-in-1 power bank.Plug your phone or device into the battery and see if it charges your phone.Wait to charge your power bank until only 1 or 2 lights are.If you charge your electronic devices at the same time, you won't have to use the power bank as quickly after it charges.