Battery does not charge if goes below 60% on my MacBook Pro 2012

If battery of my MacBook Pro 2012 goes below 60 %, it does not re charge. when I connect the charger, the green light appears and then changes to orange normally, but gets off after a few seconds. I have to disconnect it from electricity source electricity, (disconnecting of charger will not work) and then reconnect it for it to re start, but the same thing will happen again. It only charge when I close the MacBook. It continues to charge, if on re opening, the charge is above 70% or at times more