Yes but there are only 4 slots. With a 21EP, you still can equip more 2x7EP with a lvl56+ scouter if im not wrong. Total 35EP regen.
I personally don't use these things but ive seen a lot of people doing so.
I'm gonna try do this on my Turtle which already has decent ENG.

oh! i dont know that, im lvl 55 at the moment and my scouter lvl 55 cant equip all of them! :)