the cells that i have bought that had the tabing with them wern,t soldered all the way only just a little in the middle or close to the end but not up to the end so as not have the solder run and short the cell. I have done most of my cell with just a match head size solderd dot on the cell then put the on the tabbing then reheat. Just remeber to scrap the busbar or the solder will not aheir to the cell.