They're an expensive habit to acquire. The FPS is shitty out of the box, so it has to be upgraded with a new spring. Then, you gotta get new gears, a new cylinder head, a new cylinder, and all kinds of other stuff. They're very quiet, and even more so with a suppressor, but still, I don't think they're advanced enough to be skirmish worthy. The battery goes where the normaly recoil assembly would go.