Having soldered some 5000 to 6000 NiCd cells, the A123s are by comparison far more difficult. So difficult that I will not be doing it again in the future. The A123s did not have previously spot welded tages and are in fact virgin cells direct from A123.

Having conducted tests on the cells in almost a lab environment, I can only state what I found when using the MEC paste. If it works for you then thats great but I wouldnt consider using the MEC packs for applications over 35A.