A few days ago I installed the latest version of Comodo battery saver on my Samsung Galaxy S3 mini i8190n, Android version 4.1.2 and noticed that when I finish charging and unplug the cable as the notification stated, it won’t disappear automatically and I would then need to clear this notification by myself.
Without seeing your phone settings menu, I would say that what you are asking for, with respect to completely removing a system notification, would be a Mod. Is your phone rooted? Check with your phone’s boards on XDA Forums. There you will find your answer.