[Support] Battery's redstone behaviour

I'm trying to construct a simple redston mechanism to turn off my reactor when the storage batteries are full...
As i use RedPower, i use a wire that run on my wall and lead out of my house and finally at my reactor...
I use a red torch applied on top of my battery to give current to the redstone wire...
Something like this:

Where is red torch, is RP wire and is a not gate to revert the redstone signal...
The problem is that if i set the "emit if full" behaviour at the MFE, it shut off the torch on his top as i expected, but it stop to emit current as well, freezing my entire energy network...
So, if i want that my machine works again, i have to set the "nothing" behaviour to make him emit current again...
My question is: How battery behaviour exactly works? Is correct that the battery stop emit current when full or this is a bug?
Help me hunderstand, Please!

Even if i use a detector cable, i'm not sure that it can activate the RP wire.
It's an idea, but i have the necessity to make this control with RP wire because the batteries are on a wall... normal rs wire don't climb walls !
And even if it works, if my batteries are full AND there is EU consumption from my machines, the detector cable will activate the redstone wire anyway, when i don't want it...
My reactor produce really more power than my consumption, so this is a huge waste of EU if i take it on with batteries full... and there will be a little array of Solar to manage little recharge for little operation...

And last but not the last, i'm intrested to understand batteries redstone behaviour in any case!