I'm replying to this question on-list since it seems relevant. I use an 80 watt desoldering vacuum gun (one of the common "ZD" types) set to about 325C for just about all of my lead-based desoldering work. I'll occasionally have to go up to ~350 or 360 but that's pretty rare. As others have commented, you can also snip the battery legs to remove some of the thermal mass and make desoldering easier -- but I would make sure you have small, pointy cutters for that to avoid damaging the board with the cutters themselves.
-Josh > at what temperature do you prefer to hit those big solder joints on the > battery? I'd like to minimize the potential for board damage. > >
