First I would try making sure there is nothing going on with your devices USB port. Check for dust, anything in there being bent, etc. This is often the case when the phone doesn't charge, or takes forever to charge.
I know you said you replaced the cord/adapter and the battery, but what about where you are charging it? It is possible the outlet (if using an adapter) or the port on a computer/laptop (if using just a cord) is the problem. I would try charging it through a different outlet/device.
Also, did you update anything on your phone, or add any new apps, just before this started? If so, you may want to try removing the app or update and see if this resolves the problem. Strangely enough, that can cause it too.