Nothing in the system can disable charging when the charger cable is connected, so it`s prolly either, the battery or the charger. You can try carrying it to the shop where you bought it from, so they`d try a new charger(that shouldnt be a problem) before buying a new one OR it could be the batteries fault, they could just put a new one in. If your warranty still hasnt expired, then just make them switch the things.