not charging and not recognised in itunes

My Ipad3 doesn't show the lightning symbol when connected to wall charger. but after 10hours it charges 8%. I tried with another wall charger, but the result was same. till 2days ago it was charged to 100% and worked fine. what would be the problem...battery or connector strip, fuse or some other else. when connected to pc it says usb not recognized. I think the cable is good b`cause it is working fine with my iphone 4s ie..charging and connecting to iTunes. Finally I got it charged to 100% without charging icon afer 4days ie..72 hrs continuous charging. now the battery discharge is normal. can I please know the actual problem.