Recently, starting from the observation that a MBE of the electron density converges faster than a MBE for the total energy, our research group developed a density-based MBE (db-MBE) . Instead of expanding the total density, the db-MBE is based on an expansion of the total electron density of a molecular cluster in terms of electron densities of embedded monomers, dimers, trimers etc. This expansion can then be used to obtain a density-based correction to the total energy. We could show that such a db-MBE can capture many-body polarization effects in water clusters already with a two-body expansion and that accurate total and relative energies can be obtained with a densitybased two-body expansion . Here, we set out to explore the db-MBE for ion-water clusters, which present an even more challenging test case. We will particularly consider the importance of self-consistent embedding for the fragment calculations, which can be expected to be more important in ion-water clusters.