I've got these tiny little battery packs. http://hobbyking.com/hobbyking/store/catalog/70mah-20c.jpg
One of their leads appears to be made from stainless steel (at least the part that immediately protrudes from the battery, after that a piece of tinned copper is spot welded). Partly due to my lack of awareness to the material and partly because of the severe limitation in space available, I shortened the leads which has left me with only the steel part that just refuses to accept the solder and I don't have a spot welder to weld something back on.
A colleague of mine mentioned a special flux that makes stainless steel to copper soldering possible but he has long ran out of it and can't remember the name or brand.
There are many results on ebay for "stainless steel flux" but I have no idea what would work and how well. Does anybody have any experience with this sort of work or any other suggestion on how to solder it?