Fuji doesn't sell the battery holder now but here's a source for a good kit
I called Fuji a couple of years ago to order one of the AA battery holders for my GX680. The technician with whom I spoke told me that the holder was not available and had not been available for several months. Searching the web for GX680 today, I came across someone in Germany who makes what appears to be a good kit (AC/DC) for the GX680 I, II, and III. The link is http://www.gitarrenklinik.de/gx-680-battery-holder
I also ran across a firm in England which will refresh the NiCAD battery of hte GX680 for about $70 (that price is from about 2007). You may be able to find someone nearer you who refreshes NiCAD batteries.
I don't use my GX680 and I'm contemplating selling it. I just have too many cameras