I don't know this myself, I'm not into the mini's... but I'm pretty sure that searching through the forum can bring you to threads telling you the exact name/number of the fogger. Once you have that, you can go looking for other places selling that number (without the name fogger attached to it) - and sellers of those might well have spare chargers.
Sorry I can't be of more help... but I'm pretty sure this path will lead you to alternative sources. Good luck, hope you succeed.
