ac and dc conductivities of fast-ion conducting xNa2S+(1-x)B2S3 glasses in the composition range 0.001≤x≤0.1 were analyzed using the Almond-West formula σ(ν)=σdc[1+(ν/νH)α]. The hopping frequency for free charge carriers νH, the dc conductivity σdc, and their respective activation energies were determined. The concentration of free charge carriers evaluated from the conductivities and estimated mobilities is in good agreement with the overall content of sodium cations in the glasses and it is proposed that this supports the concept of a strong and not weak electrolyte model for these fast-ion conducting glasses.