How long to batteries last for a piezo bridge?

[Zaulkin]

Hi everyone,

Unfortunately for me it looks like I wont be able to get the bridge I was hoping for (an L.R. Baggs X bridge). There is still a chance I could get a different bridge and buy Ghost piezo saddles or something, but gah, I don't know. Does anyone know roughly how long a high quality 9v battery would last if using piezo pickups? I'm just curious to know. If they don't last very long I wont bother. A shame though as I already bought a 9V battery box in preparation which cost me heaps.