Several lignin based expanders underwent various physical and chemical tests. The results were compared with life time measurements for batteries with the same expanders. The aim was to gain understanding of the interactions between the expanders and the other components in the lead acid battery, and also, if possible, to find a quick and reliable screening test for the life time of batteries. The low pH of the sulphuric acid electrolyte will give both hydrolysis of the lignins and condensation. Hydrolysis seems to be detrimental to the performance. The lignosulphonate expanders seem to promote a dissolution–precipitation mechanism for lead sulphate formation.