James and others - Just wondering on your backpack sprayers, is there a switch to turn it on? I would suppose there would be, not just kick on when the pressure got too low. Where is the switch located? Is it on the wand? Or somewhere on the sprayer itself? Basically what I'm looking for, is to be able to mount a sprayer somewhere on my mower, and have a hose where I can spot spray weeds in parking lots / sidewalks, etc., without having to go back to the truck. I mow a school district, and next year I'm trying to put together a bid to get the spraying from TG / CL, and am trying to work into taking care of all the weeds that pop up in the parking lots, etc., also. Just wondering if a battery powered bp would work??? Thanks guys.