N5110 inspiron i5 power failure

My dell laptop just goes on when battey is inserted but battery is flat ...it doesnt really charge ...when i plug the charger in it just goes off...and the fan runs and then shutsdown runs and shutdowns runs and shutdown....im not sure exactly what to do....it seems as if the charger might be triping and sorting the electric plus...i can feel the electric flow on the ports when it touches my skin ....actaully at all the outputs containing metal