I tyhink one of the uses they say it was for is to lay gold plate or something, or to fuse some types of metals together .. something like that. To plate some kind of metal on to another.
There's another type of ancient device that has interested me too and that is the ancient egyptian light bulb.
Here's a carving of itin some temple or something.
And here's some scientists who remade the bulb in 1996, tested it, and found it worked.
http://therev67.tripod.com/capture.mpg
http://www.theforbiddenknowledge.com/chaptera/
the page also talks about that battery a little.