Galaxy S5 Battery Question

[Android Central Question]

I have my S5 plugged into my computer, not with the original charger. The screen comes on and its black with a grey battery and in the middle of the battery is a white lightning bolt. I have never had a Galaxy before but does that mean it is charger or is there a problem? There is nothing else on the screen and the phone won't power on. When I hold Power+Volume Down+Home I get the custom OS screen and I always choose to restart.

 

[Kodak2]

The lightning bolt indicates that it is charging. Charging from the computer will be slow, the power out from the computer is about one quarter that of the official charger so it will take a long time to charge. Best get the correct charger and official usb lead to go with the charger.