Monolithic polymer precursor of porous carbon was produced from polymerization of resorcinol-formaldehyde (RF) in the presence of cationic surfactant. The influence of concentration of the surfactant template, present in the sol-gel polymerization, on the electrochemical capacity was investigated by electrochemical impedance. It was found that a threshold concentration of surfactant is necessary to obtain sizable capacitance values. However, at higher concentrations of the surfactant, the capacitance values do not change significantly. The porous carbons have a large specific surface area (up to 671 m²/g). They also show large specific (up to 150 F/g) and volumetric capacitances (up to 130 F/cm³), in acid media. The carbon produced from the molar concentration of 0.32 M of surfactant (called carbon mesogel) was studied in detail. The products obtained from the polymerization and the thermal decomposition of the surfactant were further identified by TGA/MS analysis. The mechanical properties of the porous material show a good correlation with the values expected from the porosity present in the carbon matrix.