Disassembling seemingly welded cells

[Robert R. Daniel]

All the recent talk of duo batteries has gotten me motivated 
to rebuild a couple of mine.  But I have run into a problem.
The 4/5 non-tabbed cells in the three type III batteries I have 
cracked open (and tried to take apart) seem to be welded 
rather than merely soldered.

Or at any rate, if they are, it is a solder that will not melt or 
soften under my soldering iron.  I have actually torn the metal 
strip which conducts the electricity between cells when I tried 
to force it to separate from a cell.  And on closer inspection,
the point at which it is attached looks more like a minute 
arc-welded joint than a soldered joint.

How in the heck does one separate and remove the cells?

Thanks in advance.

Robert