Non aqueous polymer gel electrolytes based on polyethylene oxide (PEO) and ammonium hexafluorophosphate (NH4PF6) show high conductivity above 10(-2) S/cm at 25 degrees C. The addition of PEO to liquid electrolytes has been found to result in an increase in free ion concentration by dissociating ion aggregates present in these electrolytes at higher concentrations (>= 0.4 M) of NH4PF6 alongwith an increase in viscosity. The free ion concentration and viscosity play a dominant role on the conductivity behaviour of these polymer gel electrolytes at low and high concentrations of PEO respectively. The presence of ion aggregates and their dissociation with the addition of PEO has also been checked by FTIR and the results are in agreement with the conductivity behaviour.