The fiio e18 has the largest battery capacity out of the portable headphone amplifier range. Due to this they have made a feature that also allows you to charge your smartphone on the go. So you can use it as an headphone amplifier and an external battery pack charger for your Samsung Phone. There are a few things you got to do inorder to setup your headphone amplifier to charge the battery on your phone. Since a few minority of users have reported that they can't make the Fiio e18 work to charge their phone is due to wrongly setting it up. Thats why this article has been written to ensure that you know how to connect your phone to your fiio e18 amp to charge it.
1) There is a small supplied cable that provided with your amp in the box. Its a double ended mini usb cable.
2) There are two ports on the bottom of the headphone amplifier. One on the right to charge the amp and the other to use with your phone. Insert the mini usb cable into port that you use for your phone the one on the left hand side of the amp.
3) Then plug the other end of the cable into the bottom of your phone.
4) Turn on the fiio e18 amplifier and turning the volume in the middle. The amp will make a click sound that is the relay turning on the car amplifier.
5) You will then need to move the three-position switch to the 'Charge Out' option.