  The charged BTZ black hole is characterized by a power-law curvature
singularity generated by the electric charge of the hole. The curvature
singularity produces ln r terms in the asymptotic expansion of the
gravitational field and divergent contributions to the boundary terms. We show
that these boundary deformations can be generated by the action of the
conformal group in two dimensions and that an appropriate renormalization
procedure allows for the definition of finite boundary charges.
  In the semiclassical regime the central charge of the dual CFT turns out to
be that calculated by Brown and Henneaux, whereas the charge associated with
time translation is given by the renormalized black hole mass. We then show
that the Cardy formula reproduces exactly the Bekenstein-Hawking entropy of the
charged BTZ black hole.
