I am interested in getting a setup similar to that of Zakk Wylde, my personal favorite guitarist. I read a few posts on other websites about changing the regular EMGs in your gibson Les Paul to Zakks signature pickups which are active humbuckers; an 81 and an 85. The post said instead of using one 9v battery you could use use and get 18v out of your EMGs to get a really accurate sound to that of Zakk and get some real serious sustain... I am confused here, do these pickups require batteries? and if so, how would you use two at a time?