  In arXiv:0905.2622v1 and arXiv:0910.4785v1, Bray and Khuri outlined an
approach to prove the Penrose inequality for general initial data sets of the
Einstein equations. In this paper we extend this approach so that it may be
applied to a charged version of the Penrose inequality. Moreover, assuming that
the initial data is time symmetric, we prove the rigidity statement in the case
of equality for the charged Penrose inequality, a result which seems to be
absent from the literature. A new quasi-local mass, tailored to charged initial
data sets is also introduced, and used in the proof.
