John,

The button end is certainly better than the +ve end but still requires more heat and takes longer to flow than NiCds - extra heat makes me nervous. For the +ve end, I had to remove the disc to stand any chance of soldering onto the can. To be fair, I have only soldered 10 cells but will be soldering plenty more shortly. May just need to perfect the technique but give me Nicds any time for soldering!