  Using the Wald formalism, we investigate the thermodynamics of charged black
holes in D-dimensional stationary spacetimes with or without rotations in
Einstein-\ae ther-Maxwell theory. In particular, assuming the existence of a
scaling symmetry of the action, we obtain the Smarr integral formula, which can
be applied to both Killing and universal horizons. When restricted to
4-dimensional spherically symmetric spacetimes, previous results obtained by a
different method are re-derived.
