In this article we use a surface response approach to investigate the effect of iron sulphide as well as the compositions of PTFE in the overall columbic efficiency of a NiFe cell battery. Our results demonstrate that iron sulphide favours the process of charge/discharge of a NiFe cell. Our experimental results indicate iron sulphide improves the performance of a NiFe cell, but more research is still needed in order to achieve a large scale utilisation of such cells.