I am having the same issues. If I do get it to charge, it will hit 100% and stay there. If I unplug it nothing changes. If I turn it off and on and unplug the battery I can sometimes get it to come on with the correct battery status. Then other times if I plug in the USB, whether in the wall or the computer, it will not show charging or anything. It won't show mounting messages when plugged in to the computer either. I am ready to bring my phone back too. I have had the phone for about 6 months. It has been doing this for about 1 month. Anyone have a fix yet?
It seems like you are using a non official Charger.
Also car chargers can mess can up the battery.
When you Accelerate, the battery charges up sends more amps then the car charger can handle.
Although most new chargers have resistors to stop or at least lessen the effect.
But the effect seems to deteriorate with constant use.
And if you are a rough driver kiss your battery good bye.
You could fix it bye purchasing a new battery,
Peace.
IronSingh