  KASCADE-Grande is dedicated for investigations of cosmic-ray air showers in
the primary energy range from 10 PeV to 1 EeV. The multi-detector system allows
us to reconstruct charged particles, electron and muon numbers for individual
air showers with high accuracies. Based on the shower size ($N_{ch}$) spectra
of the charged particle component, the all-particle energy spectrum of cosmic
rays is reconstructed, where attenuation effects in the atmosphere are
corrected by applying the constant intensity cut method. The energy calibration
is performed by using CORSIKA simulations with high-energy interaction models
QGSJET-II-2, QGSJET-II-4, EPOS 1.99 and SIBYLL 2.1, where FLUKA has been used
as low-energy interaction model for all cases. In the different hadronic
models, different abundances for shower particles are predicted. Such model
differences in the observables will be compared and discussed in this
contribution. Furthermore, by using data with increasing statistics, the
updated energy spectra by means of different interaction models will be
presented.
