  We study a class of charged cosmological black holes defined by the
Shah-Vaidya solution, which is similar to the McVittie solution but for a
central object of nonzero electric charge. We show that the Shah-Vaidya metric
is a solution of Einstein's equations with a cuscuton and a Maxwell fields as
sources, as well as a mass parameter. We then analyze the possible causal
structures of the solution under some few physically reasonable assumptions,
and determine the regions in the parameter space corresponding to well behaved
charged cosmological black holes and those corresponding to naked
singularities. The asymptotic behavior of the Hubble factor $H(t)$ is also
determinant to the causal properties of the spacetime and a theorem explaining
its effect is stated. Examples of causal diagrams covering all the possibles
types of spacetimes allowed by our initial assumptions are drawn and discussed.
