I could have sworn that yesterday there was a thread on here about buying batteries in bulk. After searching extensively, i can't find it. Maybe i'm going crazy and imagined the whole thing. Anyway, what are some thoughts on 9v batteries for wireless mics. Over the last two years, my schools stockpile has dwindled and now we're basically out. Any tips on where to get them for cheap? Also, has anyone tried lithium batteries? http://www.flashlightsunlimited.com/lithium-9v.htm this says they last up to four times as long, but they cost basically four times as much.