Hydrogen electrosorption was performed in thin electrodeposits of Pd alloys with Pt, Au and Rh. The possibility of their application as phase charging-discharging systems was investigated. The values of specific pseudocapacitance, power and energy were calculated for hydrogen saturated Pd-rich electrodes for temperatures 283-313 K. The best working parameters are exhibited by Pd-Rh alloys with 85-95% Pd, and by Pd-Pt alloys with 90-95% Pd in the bulk. The maximum values of specific pseudocapacitance are ca. 4500 F/g, specific energy ca. 150 J/g and specific power up to 750 W/g (per the mass of the electroactive material). In the case of the alloy deposits on reticulated vitreous carbon (RVC), their characteristics related to the total mass of the electroactive material and the substrate are comparable with those for other supercapacitors utilizing various redox reactions.