  Heavy-ion collisions covering a wide range of collision energies provide a
vast amount of observables characterizing the properties of
strongly-interacting matter. In particular collisions towards the high
baryon-density regime of the QCD phase-diagram have become of interest to study
the postulated first order phase transition and to locate a possible critical
end point. In this work, the SMASH-vHLLE-hybrid is presented as a novel hybrid
model to theoretically describe such heavy-ion collisions. In addition, the
SMASH hadron resonance gas equation of state is introduced. The accuracy of the
latter is shown to be of fundamental importance in order to conserve energy,
baryon number and electric charge throughout the different stages of the hybrid
model. Furthermore, the impact of an inaccurate equation of state on final
state observables is discussed. This work constitutes a first validation of the
SMASH-vHLLE-hybrid in terms of conservation laws and excitation functions. It
is expected to be applied to a broader range of observables in the future.
