A primary cell having an anode comprising lithium and a cathode comprising iron disulfide (FeS2) and carbon particles. The cell can be in the configuration of a coin cell or the anode and cathode can be spirally wound with separator therebetween and inserted into the cell casing with electrolyte then added. The electrolyte comprises a lithium salt dissolved in a nonaqueous solvent mixture which may include an organic cyclic carbonate such as ethylene carbonate and propylene carbon. The cell after assembly is subjected to a two step preconditioning (prediscahrge) protocol involving at least two distinct discharge steps having at lease one cycle of pulsed current drain in each step and at least one rest period (step rest) between said two steps, wherein said step rest period is carried out for a period of time at above ambient temperature. The preconditioning improves cell performance.