Your everyday USB 2.0 port is all of 0.5 Amperes. And if your phone is on, it charges slowly to maybe not at all. This effect has thousands of prior discussions so I won't duplicate why here.
http://www.cnet.com/how-to/use-ampere-to-ensure-your-android-device-is-charging-properly/ notes a nice app to see more detail and a link to how to speed up charging. For me that's a simple "put the phone into airplane mode." There are other tricks and tips out there by the web load.
Bob
I am trying to learn about the differences in how my Samsung Galaxy S 5 is affected by certain charging options.
I see some USB chargers label them self as 2 amp while other are 1 amp. and then there is the computer usb ports. I thought all usb ports are equal. can some one discuss this topic. I
should I expect my phone to charge at the same speed from my computer connected usb as from my wall charger if not, why not. I notice certain chargers can not get my battery over 55% even if I leave it over night, while a newtrent battery just broght it to 100% in 45 minutes

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