This research paper reports the characteristics of dextran-glycerol-ammonium hexafluorophosphate (NH4PF6) electrolyte system and application in proton batteries. The solid polymer electrolyte films are obtained by solution cast method. Interaction between dextran, glycerol and NH4PF6 salt is examined using Fourier transform infrared spectroscopy (FTIR) analysis. Electrolyte with 18 wt. NH4PF6 exhibits the highest room temperature conductivity of (1.43 ± 0.16) � 10�4 S cm�1. It is inferred that the conductivity is mainly controlled by the changes in ionic mobility and diffusion coefficient. Field emission scanning electron microscopy (FESEM) analysis shows the difference in the morphology with respect to NH4PF6 content and verifies the conductivity result. Differential scanning calorimetry (DSC) analysis confirms that the presence of plasticizer and 18 wt. salt has decreased the glass transition temperature (Tg). The temperature dependence of conductivity for the highest conducting electrolyte shows a typical Vogel-Tamman-Fulcher (VTF) behavior. The proton batteries have been discharged at different constant currents. © 2022 Hydrogen Energy Publications LLC