Is it possible to interupt the charger? I have settings in my android (5.0.2) that the screen is always on while charging. So charging = on, not charging it will automatically go off. Now you only need to interupt the power supply. I am sure your tablet battery will survive the night without power ...

you have something appropriate to the script, or only copy/paste?
My Archos tablet stopt by the step '9. Else if'. I have follow the steps of http://i.imgur.com/ixWxdbB.png / http://i.imgur.com/4WSl1On.png